From 8b1471dc086828d0c7fe10eac2afc117b23e8ec9 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Sat, 27 Feb 2021 11:22:59 +0100
Subject: [PATCH 1/8] Add support for object type spreading

```rescript
type a = {"x": int}
type u = {...a, "y": int}
```
---
 src/res_core.ml                               | 25 +++++++++++++++++++
 src/res_grammar.ml                            |  2 +-
 src/res_printer.ml                            |  6 ++++-
 .../typexpr/__snapshots__/parse.spec.js.snap  |  7 ++++++
 .../grammar/typexpr/objectTypeSpreading.res   |  4 +++
 .../typexpr/__snapshots__/render.spec.js.snap |  8 ++++++
 tests/printer/typexpr/objectTypeSpreading.res |  4 +++
 7 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 tests/parsing/grammar/typexpr/objectTypeSpreading.res
 create mode 100644 tests/printer/typexpr/objectTypeSpreading.res

diff --git a/src/res_core.ml b/src/res_core.ml
index a98aa451..57625108 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -4130,6 +4130,10 @@ and parseStringFieldDeclaration p =
     Parser.expect ~grammar:Grammar.TypeExpression Colon p;
     let typ = parsePolyTypeExpr p in
     Some(Parsetree.Otag (fieldName, attrs, typ))
+  | DotDotDot ->
+    Parser.next p;
+    let typ = parseTypExpr p in
+    Some(Parsetree.Oinherit typ)
   | Lident name ->
     let nameLoc = mkLoc p.startPos p.endPos in
     Parser.err p (Diagnostics.message "An inline record type declaration is only allowed in a variant constructor's declaration");
@@ -4633,6 +4637,27 @@ and parseRecordOrBsObjectDecl p =
     in
     let typ = parseArrowTypeRest ~es6Arrow:true ~startPos typ p in
     (Some typ, Asttypes.Public, Parsetree.Ptype_abstract)
+   | DotDotDot ->
+    (* start of object type spreading, e.g. `type u = {...a, "u": int}` *)
+    Parser.next p;
+    let typ = parseTypExpr p in
+    Parser.expect Comma p;
+    let fields =
+      (Parsetree.Oinherit typ)::(
+        parseCommaDelimitedRegion
+          ~grammar:Grammar.StringFieldDeclarations
+          ~closing:Rbrace
+          ~f:parseStringFieldDeclaration
+          p
+      )
+    in
+    Parser.expect Rbrace p;
+    let loc = mkLoc startPos p.prevEndPos in
+    let typ =
+      Ast_helper.Typ.object_ ~loc fields Asttypes.Closed |> parseTypeAlias p
+    in
+    let typ = parseArrowTypeRest ~es6Arrow:true ~startPos typ p in
+    (Some typ, Asttypes.Public, Parsetree.Ptype_abstract)
   | _ ->
     let attrs = parseAttributes p in
     begin match p.Parser.token with
diff --git a/src/res_grammar.ml b/src/res_grammar.ml
index e2b2b317..99e74201 100644
--- a/src/res_grammar.ml
+++ b/src/res_grammar.ml
@@ -211,7 +211,7 @@ let isParameterStart = function
 
 (* TODO: overparse Uident ? *)
 let isStringFieldDeclStart = function
-  | Token.String _ | Lident _ | At -> true
+  | Token.String _ | Lident _ | At | DotDotDot -> true
   | _ -> false
 
 (* TODO: overparse Uident ? *)
diff --git a/src/res_printer.ml b/src/res_printer.ml
index ab6dc43a..a3547470 100644
--- a/src/res_printer.ml
+++ b/src/res_printer.ml
@@ -1761,7 +1761,11 @@ and printObjectField (field : Parsetree.object_field) cmtTbl =
     ] in
     let cmtLoc = {labelLoc.loc with loc_end = typ.ptyp_loc.loc_end} in
     printComments doc cmtTbl cmtLoc
-  | _ -> Doc.nil
+  | Oinherit typexpr ->
+    Doc.concat [
+      Doc.dotdotdot;
+      printTypExpr typexpr cmtTbl
+    ]
 
 (* es6 arrow type arg
  * type t = (~foo: string, ~bar: float=?, unit) => unit
diff --git a/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap b/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap
index 59586f00..66f254ac 100644
--- a/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap
+++ b/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap
@@ -119,6 +119,13 @@ type nonrec t = (module Console) ref
 let (devices : (string, (module DEVICE)) Hastbl.t) = Hashtbl.creat 17"
 `;
 
+exports[`objectTypeSpreading.res 1`] = `
+"type nonrec a = < x: int   > 
+type nonrec u = < a ;u: int   > 
+type nonrec v = < v: int  ;a  > 
+type nonrec w = < j: int  ;a ;k: int  ;v  > "
+`;
+
 exports[`parenthesized.res 1`] = `"type nonrec t = ((a:((int)[@ns.namedArgLoc ]) -> unit)[@attr ])"`;
 
 exports[`poly.res 1`] = `
diff --git a/tests/parsing/grammar/typexpr/objectTypeSpreading.res b/tests/parsing/grammar/typexpr/objectTypeSpreading.res
new file mode 100644
index 00000000..03343b15
--- /dev/null
+++ b/tests/parsing/grammar/typexpr/objectTypeSpreading.res
@@ -0,0 +1,4 @@
+type a = {"x": int}
+type u = {...a, "u": int}
+type v = {"v": int, ...a}
+type w = {"j": int, ...a, "k": int, ...v}
diff --git a/tests/printer/typexpr/__snapshots__/render.spec.js.snap b/tests/printer/typexpr/__snapshots__/render.spec.js.snap
index a1a07b28..2efd1265 100644
--- a/tests/printer/typexpr/__snapshots__/render.spec.js.snap
+++ b/tests/printer/typexpr/__snapshots__/render.spec.js.snap
@@ -409,6 +409,14 @@ let devices: @attr Hastbl.t<string, module(DEVICE)> = xyz
 "
 `;
 
+exports[`objectTypeSpreading.res 1`] = `
+"type a = {\\"x\\": int}
+type u = {...a, \\"u\\": int}
+type v = {\\"v\\": int, ...a}
+type w = {\\"j\\": int, ...a, \\"k\\": int, ...v}
+"
+`;
+
 exports[`polyTyp.res 1`] = `
 "external getLogger: unit => {
   \\"log\\": 'a => unit,
diff --git a/tests/printer/typexpr/objectTypeSpreading.res b/tests/printer/typexpr/objectTypeSpreading.res
new file mode 100644
index 00000000..03343b15
--- /dev/null
+++ b/tests/printer/typexpr/objectTypeSpreading.res
@@ -0,0 +1,4 @@
+type a = {"x": int}
+type u = {...a, "u": int}
+type v = {"v": int, ...a}
+type w = {"j": int, ...a, "k": int, ...v}

From 69fd8ccc87add5ea1fa39b4ca8a63e0b2e083628 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Sun, 28 Feb 2021 08:08:53 +0100
Subject: [PATCH 2/8] Improve test coverage for object type spread.

---
 src/res_core.ml                               | 29 +++++++++++++
 .../typexpr/__snapshots__/parse.spec.js.snap  | 37 +++++++++++++++-
 .../grammar/typexpr/objectTypeSpreading.res   | 36 ++++++++++++++++
 .../typexpr/__snapshots__/render.spec.js.snap | 42 +++++++++++++++++++
 tests/printer/typexpr/objectTypeSpreading.res | 36 ++++++++++++++++
 5 files changed, 179 insertions(+), 1 deletion(-)

diff --git a/src/res_core.ml b/src/res_core.ml
index 57625108..0f31e170 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -4260,6 +4260,35 @@ and parseConstrDeclArgs p =
         in
         Parser.expect Rparen p;
         Parsetree.Pcstr_tuple (typ::moreArgs)
+      | DotDotDot ->
+        (* start of object type spreading, e.g. `User({...a, "u": int})` *)
+        Parser.next p;
+        let typ = parseTypExpr p in
+        Parser.expect Comma p;
+        let fields =
+          (Parsetree.Oinherit typ)::(
+            parseCommaDelimitedRegion
+              ~grammar:Grammar.StringFieldDeclarations
+              ~closing:Rbrace
+              ~f:parseStringFieldDeclaration
+              p
+          )
+        in
+        Parser.expect Rbrace p;
+        let loc = mkLoc startPos p.prevEndPos in
+        let typ =
+          Ast_helper.Typ.object_ ~loc fields Asttypes.Closed |> parseTypeAlias p
+        in
+        let typ = parseArrowTypeRest ~es6Arrow:true ~startPos typ p in
+        Parser.optional p Comma |> ignore;
+        let moreArgs =
+          parseCommaDelimitedRegion
+            ~grammar:Grammar.TypExprList
+            ~closing:Rparen
+            ~f:parseTypExprRegion p
+        in
+        Parser.expect Rparen p;
+        Parsetree.Pcstr_tuple (typ::moreArgs)
       | _ ->
         let attrs = parseAttributes p in
         begin match p.Parser.token with
diff --git a/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap b/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap
index 66f254ac..d59ba55c 100644
--- a/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap
+++ b/tests/parsing/grammar/typexpr/__snapshots__/parse.spec.js.snap
@@ -123,7 +123,42 @@ exports[`objectTypeSpreading.res 1`] = `
 "type nonrec a = < x: int   > 
 type nonrec u = < a ;u: int   > 
 type nonrec v = < v: int  ;a  > 
-type nonrec w = < j: int  ;a ;k: int  ;v  > "
+type nonrec w = < j: int  ;a ;k: int  ;v  > 
+type nonrec t = < a ;u: int   >  as 'a
+type nonrec t = < a ;u: int   >  -> unit
+type nonrec t = (< a ;u: int   >  as 'a) -> unit
+type nonrec t = < a ;u: int   >  -> < a ;v: int   >  -> unit
+type nonrec user = < name: string   > 
+let (steve : < user ;age: int   > ) = [%obj { name = \\"Steve\\"; age = 30 }]
+let steve = ([%obj { name = \\"Steve\\"; age = 30 }] : < user ;age: int   > )
+let steve = ((([%obj { name = \\"Steve\\"; age = 30 }] : < user ;age: int   > ))
+  [@ns.braces ])
+let printFullUser (steve : < user ;age: int   > ) = Js.log steve
+let printFullUser ~user:(((user : < user ;age: int   > ))[@ns.namedArgLoc ]) 
+  = Js.log steve
+let printFullUser ~user:(((user : < user ;age: int   > ))[@ns.namedArgLoc ]) 
+  = Js.log steve
+let printFullUser ?user:(((user)[@ns.namedArgLoc ])=
+  (steve : < user ;age: int   > ))  = Js.log steve
+external steve : < user ;age: int   >  = \\"steve\\"[@@val ]
+let makeCeoOf30yearsOld name =
+  ([%obj { name; age = 30 }] : < user ;age: int   > )
+type nonrec optionalUser = < user ;age: int   >  option
+type nonrec optionalTupleUser =
+  (< user ;age: int   >  * < user ;age: int   > ) option
+type nonrec constrUser =
+  (< user ;age: int   > , < user ;age: int   > ) myTypeConstructor
+type nonrec taggedUser =
+  | User of < user ;age: int   >  
+  | Ceo of < user ;age: int  ;direction: bool   >  *
+  < salary ;taxFraud: bool   >  
+type nonrec polyTaggedUser = [ \`User of < user ;age: int   >  ]
+type nonrec polyTaggedUser2 =
+  [ \`User of < user ;age: int   >  
+  | \`Ceo of
+      (< user ;age: int  ;direction: bool   >  *
+        < salary ;taxFraud: bool   > )
+      ]"
 `;
 
 exports[`parenthesized.res 1`] = `"type nonrec t = ((a:((int)[@ns.namedArgLoc ]) -> unit)[@attr ])"`;
diff --git a/tests/parsing/grammar/typexpr/objectTypeSpreading.res b/tests/parsing/grammar/typexpr/objectTypeSpreading.res
index 03343b15..216d4000 100644
--- a/tests/parsing/grammar/typexpr/objectTypeSpreading.res
+++ b/tests/parsing/grammar/typexpr/objectTypeSpreading.res
@@ -2,3 +2,39 @@ type a = {"x": int}
 type u = {...a, "u": int}
 type v = {"v": int, ...a}
 type w = {"j": int, ...a, "k": int, ...v}
+
+
+type t = {...a, "u": int} as 'a 
+type t = {...a, "u": int} => unit
+type t = {...a, "u": int} as 'a => unit
+type t = ({...a, "u": int}, {...a, "v": int}) => unit
+
+type user = {"name": string} 
+
+let steve: {...user, "age": int} = {"name": "Steve", "age": 30}
+let steve = ({"name": "Steve", "age": 30}: {...user, "age": int})
+let steve = {({"name": "Steve", "age": 30}: {...user, "age": int})}
+
+let printFullUser = (steve: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user = steve : {...user, "age": int}) => Js.log(steve)
+
+@val
+external steve: {...user, "age": int} = "steve"
+
+let makeCeoOf30yearsOld = (name) : {...user, "age": int} => {"name": name, "age": 30}
+
+type optionalUser = option<{...user, "age": int}>
+type optionalTupleUser = option<({...user, "age": int}, {...user, "age": int})>
+type constrUser = myTypeConstructor<{...user, "age": int}, {...user, "age": int}>
+
+type taggedUser =
+  | User({...user, "age": int})
+  | Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool}) 
+
+type polyTaggedUser = [ #User({...user, "age": int}) ]
+type polyTaggedUser2 = [ 
+  | #User({...user, "age": int}) 
+  | #Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool}) 
+]
diff --git a/tests/printer/typexpr/__snapshots__/render.spec.js.snap b/tests/printer/typexpr/__snapshots__/render.spec.js.snap
index 2efd1265..b53c5cc6 100644
--- a/tests/printer/typexpr/__snapshots__/render.spec.js.snap
+++ b/tests/printer/typexpr/__snapshots__/render.spec.js.snap
@@ -414,6 +414,48 @@ exports[`objectTypeSpreading.res 1`] = `
 type u = {...a, \\"u\\": int}
 type v = {\\"v\\": int, ...a}
 type w = {\\"j\\": int, ...a, \\"k\\": int, ...v}
+
+type t = {...a, \\"u\\": int} as 'a
+type t = {...a, \\"u\\": int} => unit
+type t = ({...a, \\"u\\": int} as 'a) => unit
+type t = ({...a, \\"u\\": int}, {...a, \\"v\\": int}) => unit
+
+type user = {\\"name\\": string}
+
+let steve: {...user, \\"age\\": int} = {\\"name\\": \\"Steve\\", \\"age\\": 30}
+let steve = ({\\"name\\": \\"Steve\\", \\"age\\": 30}: {...user, \\"age\\": int})
+let steve = {({\\"name\\": \\"Steve\\", \\"age\\": 30}: {...user, \\"age\\": int})}
+
+let printFullUser = (steve: {...user, \\"age\\": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, \\"age\\": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, \\"age\\": int}) => Js.log(steve)
+let printFullUser = (~user=steve: {...user, \\"age\\": int}) => Js.log(steve)
+
+@val
+external steve: {...user, \\"age\\": int} = \\"steve\\"
+
+let makeCeoOf30yearsOld = (name): {...user, \\"age\\": int} =>
+  {\\"name\\": name, \\"age\\": 30}
+
+type optionalUser = option<{...user, \\"age\\": int}>
+type optionalTupleUser = option<({...user, \\"age\\": int}, {...user, \\"age\\": int})>
+type constrUser = myTypeConstructor<
+  {...user, \\"age\\": int},
+  {...user, \\"age\\": int},
+>
+
+type taggedUser =
+  | User({...user, \\"age\\": int})
+  | Ceo({...user, \\"age\\": int, \\"direction\\": bool}, {...salary, \\"taxFraud\\": bool})
+
+type polyTaggedUser = [#User({...user, \\"age\\": int})]
+type polyTaggedUser2 = [
+  | #User({...user, \\"age\\": int})
+  | #Ceo(
+    {...user, \\"age\\": int, \\"direction\\": bool},
+    {...salary, \\"taxFraud\\": bool},
+  )
+]
 "
 `;
 
diff --git a/tests/printer/typexpr/objectTypeSpreading.res b/tests/printer/typexpr/objectTypeSpreading.res
index 03343b15..216d4000 100644
--- a/tests/printer/typexpr/objectTypeSpreading.res
+++ b/tests/printer/typexpr/objectTypeSpreading.res
@@ -2,3 +2,39 @@ type a = {"x": int}
 type u = {...a, "u": int}
 type v = {"v": int, ...a}
 type w = {"j": int, ...a, "k": int, ...v}
+
+
+type t = {...a, "u": int} as 'a 
+type t = {...a, "u": int} => unit
+type t = {...a, "u": int} as 'a => unit
+type t = ({...a, "u": int}, {...a, "v": int}) => unit
+
+type user = {"name": string} 
+
+let steve: {...user, "age": int} = {"name": "Steve", "age": 30}
+let steve = ({"name": "Steve", "age": 30}: {...user, "age": int})
+let steve = {({"name": "Steve", "age": 30}: {...user, "age": int})}
+
+let printFullUser = (steve: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user = steve : {...user, "age": int}) => Js.log(steve)
+
+@val
+external steve: {...user, "age": int} = "steve"
+
+let makeCeoOf30yearsOld = (name) : {...user, "age": int} => {"name": name, "age": 30}
+
+type optionalUser = option<{...user, "age": int}>
+type optionalTupleUser = option<({...user, "age": int}, {...user, "age": int})>
+type constrUser = myTypeConstructor<{...user, "age": int}, {...user, "age": int}>
+
+type taggedUser =
+  | User({...user, "age": int})
+  | Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool}) 
+
+type polyTaggedUser = [ #User({...user, "age": int}) ]
+type polyTaggedUser2 = [ 
+  | #User({...user, "age": int}) 
+  | #Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool}) 
+]

From be83c83c0d9fa85fbd26cff53faa58eec278bcc9 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Sun, 28 Feb 2021 11:03:08 +0100
Subject: [PATCH 3/8] Cleanup function names containing "BsObject"

---
 src/res_core.ml | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/res_core.ml b/src/res_core.ml
index 0f31e170..412b1e47 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -3766,7 +3766,7 @@ and parseAtomicTypExpr ~attrs p =
     let loc = mkLoc startPos p.prevEndPos in
     Ast_helper.Typ.extension ~attrs ~loc extension
   | Lbrace ->
-    parseRecordOrBsObjectType ~attrs p
+    parseRecordOrObjectType ~attrs p
   | token ->
     Parser.err p (Diagnostics.unexpected token p.breadcrumbs);
     begin match skipTokensAndMaybeRetry p ~isStartOfGrammar:Grammar.isAtomicTypExprStart with
@@ -3825,7 +3825,7 @@ and parsePackageConstraint p =
     Some (typeConstr, typ)
   | _ -> None
 
-and parseRecordOrBsObjectType ~attrs p =
+and parseRecordOrObjectType ~attrs p =
   (* for inline record in constructor *)
   let startPos = p.Parser.startPos in
   Parser.expect Lbrace p;
@@ -4641,7 +4641,7 @@ and parseTypeEquationOrConstrDecl p =
     (* TODO: is this a good idea? *)
     (None, Asttypes.Public, Parsetree.Ptype_abstract)
 
-and parseRecordOrBsObjectDecl p =
+and parseRecordOrObjectDecl p =
   let startPos = p.Parser.startPos in
   Parser.expect Lbrace p;
   match p.Parser.token with
@@ -4777,7 +4777,7 @@ and parsePrivateEqOrRepr p =
   Parser.expect Private p;
   match p.Parser.token with
   | Lbrace ->
-    let (manifest, _ ,kind) = parseRecordOrBsObjectDecl p in
+    let (manifest, _ ,kind) = parseRecordOrObjectDecl p in
     (manifest, Asttypes.Private, kind)
   | Uident _ ->
     let (manifest, _, kind) = parseTypeEquationOrConstrDecl p in
@@ -4979,7 +4979,7 @@ and parseTypeEquationAndRepresentation p =
     | Uident _ ->
       parseTypeEquationOrConstrDecl p
     | Lbrace ->
-      parseRecordOrBsObjectDecl p
+      parseRecordOrObjectDecl p
     | Private ->
       parsePrivateEqOrRepr p
     | Bar | DotDot ->

From b1f34093d9b5aa45945111d00a92c62d3f9e2b62 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Sun, 28 Feb 2021 11:41:00 +0100
Subject: [PATCH 4/8] Improve error messages when user tries to mix
 object/record declaration with spreading.

---
 src/res_core.ml                               | 32 ++++++++-
 .../typexpr/__snapshots__/parse.spec.js.snap  | 65 +++++++++++++++++++
 tests/parsing/errors/typexpr/objectSpread.res |  9 +++
 3 files changed, 105 insertions(+), 1 deletion(-)
 create mode 100644 tests/parsing/errors/typexpr/objectSpread.res

diff --git a/src/res_core.ml b/src/res_core.ml
index 412b1e47..960b4e19 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -112,6 +112,15 @@ Solution: directly use `concat`."
 
   let stringInterpolationInPattern =
     "String interpolation is not supported in pattern matching."
+
+  let spreadInRecordDeclaration =
+    "A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does."
+
+  let objectQuotedFieldName name =
+    "An object type declaration needs quoted field names. Did you mean \"" ^ name ^ "\"?"
+
+  let forbiddenInlineRecordDeclaration =
+    "An inline record type declaration is only allowed in a variant constructor's declaration"
 end
 
 
@@ -3834,6 +3843,11 @@ and parseRecordOrObjectType ~attrs p =
   | Dot -> Parser.next p; Asttypes.Closed
   | _ -> Asttypes.Closed
   in
+  let () = match p.token with
+  | Lident _ ->
+    Parser.err p (Diagnostics.message ErrorMessages.forbiddenInlineRecordDeclaration)
+  | _ -> ()
+  in
   let fields =
     parseCommaDelimitedRegion
       ~grammar:Grammar.StringFieldDeclarations
@@ -4136,7 +4150,7 @@ and parseStringFieldDeclaration p =
     Some(Parsetree.Oinherit typ)
   | Lident name ->
     let nameLoc = mkLoc p.startPos p.endPos in
-    Parser.err p (Diagnostics.message "An inline record type declaration is only allowed in a variant constructor's declaration");
+    Parser.err p (Diagnostics.message (ErrorMessages.objectQuotedFieldName name));
     Parser.next p;
     let fieldName = Location.mkloc name nameLoc in
     Parser.expect ~grammar:Grammar.TypeExpression Colon p;
@@ -4261,10 +4275,18 @@ and parseConstrDeclArgs p =
         Parser.expect Rparen p;
         Parsetree.Pcstr_tuple (typ::moreArgs)
       | DotDotDot ->
+        let dotdotdotStart = p.startPos in
+        let dotdotdotEnd = p.endPos in
         (* start of object type spreading, e.g. `User({...a, "u": int})` *)
         Parser.next p;
         let typ = parseTypExpr p in
         Parser.expect Comma p;
+        let () = match p.token with
+        | Lident _ ->
+          Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
+            (Diagnostics.message ErrorMessages.spreadInRecordDeclaration)
+        | _ -> ()
+        in
         let fields =
           (Parsetree.Oinherit typ)::(
             parseCommaDelimitedRegion
@@ -4667,10 +4689,18 @@ and parseRecordOrObjectDecl p =
     let typ = parseArrowTypeRest ~es6Arrow:true ~startPos typ p in
     (Some typ, Asttypes.Public, Parsetree.Ptype_abstract)
    | DotDotDot ->
+    let dotdotdotStart = p.startPos in
+    let dotdotdotEnd = p.endPos in
     (* start of object type spreading, e.g. `type u = {...a, "u": int}` *)
     Parser.next p;
     let typ = parseTypExpr p in
     Parser.expect Comma p;
+    let () = match p.token with
+    | Lident _ ->
+      Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
+        (Diagnostics.message ErrorMessages.spreadInRecordDeclaration)
+    | _ -> ()
+    in
     let fields =
       (Parsetree.Oinherit typ)::(
         parseCommaDelimitedRegion
diff --git a/tests/parsing/errors/typexpr/__snapshots__/parse.spec.js.snap b/tests/parsing/errors/typexpr/__snapshots__/parse.spec.js.snap
index af65d7ae..682bebbe 100644
--- a/tests/parsing/errors/typexpr/__snapshots__/parse.spec.js.snap
+++ b/tests/parsing/errors/typexpr/__snapshots__/parse.spec.js.snap
@@ -219,6 +219,71 @@ external printName : name:((unit)[@ns.namedArgLoc ]) -> unit = \\"printName\\"
   I'm not sure what to parse here when looking at \\"?\\".
 
 
+========================================================"
+`;
+
+exports[`objectSpread.res 1`] = `
+"=====Parsetree==========================================
+type nonrec u = < a ;u: int   > 
+type nonrec u = private < a ;u: int   > 
+type nonrec x =
+  | Type of < a ;u: int   >  
+type nonrec u = < a ;u: int  ;v: int   > 
+let f (x : < a: int  ;b: int   > ) = ()
+=====Errors=============================================
+
+  Syntax error!
+  parsing/errors/typexpr/objectSpread.res:1:11-13
+  1 │ type u = {...a, u: int}
+  2 │ 
+  3 │ type u = private {...a, u: int}
+
+  A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does.
+
+
+  Syntax error!
+  parsing/errors/typexpr/objectSpread.res:3:19-21
+  1 │ type u = {...a, u: int}
+  2 │ 
+  3 │ type u = private {...a, u: int}
+  4 │ 
+  5 │ type x = Type({...a, u: int})
+
+  A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does.
+
+
+  Syntax error!
+  parsing/errors/typexpr/objectSpread.res:5:16-18
+  3 │ type u = private {...a, u: int}
+  4 │ 
+  5 │ type x = Type({...a, u: int})
+  6 │ 
+  7 │ type u = {...a, \\"u\\": int, v: int}
+
+  A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does.
+
+
+  Syntax error!
+  parsing/errors/typexpr/objectSpread.res:7:27
+  5 │ type x = Type({...a, u: int})
+  6 │ 
+  7 │ type u = {...a, \\"u\\": int, v: int}
+  8 │ 
+  9 │ let f = (x: {a: int, b: int}) => ()
+
+  An object type declaration needs quoted field names. Did you mean \\"v\\"?
+
+
+  Syntax error!
+  parsing/errors/typexpr/objectSpread.res:9:14
+   7 │ type u = {...a, \\"u\\": int, v: int}
+   8 │ 
+   9 │ let f = (x: {a: int, b: int}) => ()
+  10 │ 
+
+  An inline record type declaration is only allowed in a variant constructor's declaration
+
+
 ========================================================"
 `;
 
diff --git a/tests/parsing/errors/typexpr/objectSpread.res b/tests/parsing/errors/typexpr/objectSpread.res
new file mode 100644
index 00000000..c4e7db71
--- /dev/null
+++ b/tests/parsing/errors/typexpr/objectSpread.res
@@ -0,0 +1,9 @@
+type u = {...a, u: int}
+
+type u = private {...a, u: int}
+
+type x = Type({...a, u: int})
+
+type u = {...a, "u": int, v: int}
+
+let f = (x: {a: int, b: int}) => ()

From bacf061a53c2ed2af276d83c5704438b49d50f35 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Mon, 15 Mar 2021 07:55:26 +0100
Subject: [PATCH 5/8] Fix printing of open objects with spread.

---
 src/res_printer.ml                                |  9 ++++++++-
 .../reason/__snapshots__/render.spec.js.snap      |  8 ++++++++
 tests/conversion/reason/object.ml                 |  4 ++++
 .../typexpr/__snapshots__/render.spec.js.snap     | 15 +++++++++++++++
 tests/printer/typexpr/objectTypeSpreading.res     |  5 +++++
 5 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 tests/conversion/reason/object.ml

diff --git a/src/res_printer.ml b/src/res_printer.ml
index a3547470..83ea99d8 100644
--- a/src/res_printer.ml
+++ b/src/res_printer.ml
@@ -1712,7 +1712,14 @@ and printObject ~inline fields openFlag cmtTbl =
       Doc.lbrace;
       (match openFlag with
       | Asttypes.Closed -> Doc.nil
-      | Open -> Doc.dotdot);
+      | Open ->
+        begin match fields with
+        (* handle `type t = {.. ...objType, "x": int}`
+         * .. and ... should have a space in between *)
+        | (Oinherit _)::_ -> Doc.text ".. "
+        | _ -> Doc.dotdot
+        end
+      );
       Doc.indent (
         Doc.concat [
           Doc.softLine;
diff --git a/tests/conversion/reason/__snapshots__/render.spec.js.snap b/tests/conversion/reason/__snapshots__/render.spec.js.snap
index 77c346e2..113140cb 100644
--- a/tests/conversion/reason/__snapshots__/render.spec.js.snap
+++ b/tests/conversion/reason/__snapshots__/render.spec.js.snap
@@ -1430,6 +1430,14 @@ let make = (
 "
 `;
 
+exports[`object.ml 1`] = `
+"type hi = {\\"z\\": int}
+type u<'a> = {.. ...hi, \\"x\\": int, \\"y\\": int} as 'a
+type u1<'a> = {.. ...hi} as 'a
+type u2<'a> = {.. ...hi, ...hi, \\"y\\": int, ...hi} as 'a
+"
+`;
+
 exports[`openPattern.re 1`] = `
 "let {T.a: a} = a()
 let [Color.Blue] = a()
diff --git a/tests/conversion/reason/object.ml b/tests/conversion/reason/object.ml
new file mode 100644
index 00000000..62099596
--- /dev/null
+++ b/tests/conversion/reason/object.ml
@@ -0,0 +1,4 @@
+type hi = < z : int >
+type 'a u = < hi ; x : int ; y : int; .. >  as 'a
+type 'a u1 = < hi; .. > as 'a
+type 'a u2 = < hi ; hi; y : int ; hi; .. >  as 'a
diff --git a/tests/printer/typexpr/__snapshots__/render.spec.js.snap b/tests/printer/typexpr/__snapshots__/render.spec.js.snap
index b53c5cc6..2db99f9b 100644
--- a/tests/printer/typexpr/__snapshots__/render.spec.js.snap
+++ b/tests/printer/typexpr/__snapshots__/render.spec.js.snap
@@ -456,6 +456,21 @@ type polyTaggedUser2 = [
     {...salary, \\"taxFraud\\": bool},
   )
 ]
+
+// notice .. and ..., they should have a space
+type u<'a> = {.. ...hi} as 'a
+type u<'a> = {..
+  ...hi,
+  \\"superLongFieldName\\": string,
+  \\"superLongFieldName22222222222\\": int,
+} as 'a
+type u<'a> = {..
+  ...hi,
+  \\"superLongFieldName\\": string,
+  ...hi,
+  \\"superLongFieldName22222222222\\": int,
+  ...hi,
+} as 'a
 "
 `;
 
diff --git a/tests/printer/typexpr/objectTypeSpreading.res b/tests/printer/typexpr/objectTypeSpreading.res
index 216d4000..8e2d2e05 100644
--- a/tests/printer/typexpr/objectTypeSpreading.res
+++ b/tests/printer/typexpr/objectTypeSpreading.res
@@ -38,3 +38,8 @@ type polyTaggedUser2 = [
   | #User({...user, "age": int}) 
   | #Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool}) 
 ]
+
+// notice .. and ..., they should have a space
+type u<'a> = {.. ...hi} as 'a
+type u<'a> = {.. ...hi, "superLongFieldName": string, "superLongFieldName22222222222": int} as 'a
+type u<'a> = {.. ...hi, "superLongFieldName": string, ...hi, "superLongFieldName22222222222": int, ...hi} as 'a

From 14bcd866ed6efacd5eacac327731c27a3e0b585a Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Tue, 23 Mar 2021 18:52:56 +0100
Subject: [PATCH 6/8] Implement error message for ambiguous record spread or
 object type spread.

---
 src/res_core.ml                               | 19 +++++++++--
 .../other/__snapshots__/parse.spec.js.snap    | 33 ++++++++++++++++---
 tests/parsing/errors/other/spread.res         |  3 ++
 3 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/src/res_core.ml b/src/res_core.ml
index 960b4e19..9d9810c8 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -121,6 +121,9 @@ Solution: directly use `concat`."
 
   let forbiddenInlineRecordDeclaration =
     "An inline record type declaration is only allowed in a variant constructor's declaration"
+
+  let ambiguousRecordSpread =
+    "The … spread is only supported for record value update and object type declaration."
 end
 
 
@@ -4280,7 +4283,13 @@ and parseConstrDeclArgs p =
         (* start of object type spreading, e.g. `User({...a, "u": int})` *)
         Parser.next p;
         let typ = parseTypExpr p in
-        Parser.expect Comma p;
+        let () = match p.token with
+        | Rbrace ->
+          Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
+            (Diagnostics.message ErrorMessages.ambiguousRecordSpread);
+          Parser.next p;
+        | _ -> Parser.expect Comma p
+        in
         let () = match p.token with
         | Lident _ ->
           Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
@@ -4694,7 +4703,13 @@ and parseRecordOrObjectDecl p =
     (* start of object type spreading, e.g. `type u = {...a, "u": int}` *)
     Parser.next p;
     let typ = parseTypExpr p in
-    Parser.expect Comma p;
+    let () = match p.token with
+    | Rbrace ->
+      Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
+        (Diagnostics.message ErrorMessages.ambiguousRecordSpread);
+      Parser.next p;
+    | _ -> Parser.expect Comma p
+    in
     let () = match p.token with
     | Lident _ ->
       Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
diff --git a/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap b/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap
index 1beca263..6dcaf4b1 100644
--- a/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap
+++ b/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap
@@ -166,6 +166,9 @@ let record = { x with y }
 let { x; y } = myRecord
 let myList = x :: y
 let x::y = myList
+type nonrec t = < a  > 
+type nonrec t =
+  | Foo of < a  >  
 =====Errors=============================================
 
   Syntax error!
@@ -216,14 +219,36 @@ Solution: you need to pull out each field you want explicitly.
 
   Syntax error!
   parsing/errors/other/spread.res:8:13-22
-  6 │ 
-  7 │ let myList = list{...x, ...y}
-  8 │ let list{...x, ...y} = myList
-  9 │ 
+   6 │ 
+   7 │ let myList = list{...x, ...y}
+   8 │ let list{...x, ...y} = myList
+   9 │ 
+  10 │ type t = {...a}
 
   List pattern matches only supports one \`...\` spread, at the end.
 Explanation: a list spread at the tail is efficient, but a spread in the middle would create new list[s]; out of performance concern, our pattern matching currently guarantees to never create new intermediate data.
 
 
+  Syntax error!
+  parsing/errors/other/spread.res:10:11-13
+   8 │ let list{...x, ...y} = myList
+   9 │ 
+  10 │ type t = {...a}
+  11 │ type t = Foo({...a})
+  12 │ 
+
+  The … spread is only supported for record value update and object type declaration.
+
+
+  Syntax error!
+  parsing/errors/other/spread.res:11:15-17
+   9 │ 
+  10 │ type t = {...a}
+  11 │ type t = Foo({...a})
+  12 │ 
+
+  The … spread is only supported for record value update and object type declaration.
+
+
 ========================================================"
 `;
diff --git a/tests/parsing/errors/other/spread.res b/tests/parsing/errors/other/spread.res
index 39be7c29..5ed52108 100644
--- a/tests/parsing/errors/other/spread.res
+++ b/tests/parsing/errors/other/spread.res
@@ -6,3 +6,6 @@ let {...x, ...y} = myRecord
 
 let myList = list{...x, ...y}
 let list{...x, ...y} = myList
+
+type t = {...a}
+type t = Foo({...a})

From 1bb58dd002a5f437e1096cd7ce42da7ad28f26a3 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Thu, 25 Mar 2021 07:00:53 +0100
Subject: [PATCH 7/8] Improve spreading without extra fields error message.

---
 src/res_core.ml                               | 18 ++++--
 .../conversion/reason/expected/object.ml.txt  |  4 ++
 .../errors/other/expected/spread.res.txt      | 50 +++++++++++++--
 tests/parsing/errors/other/spread.res         |  1 +
 .../typexpr/expected/objectSpread.res.txt     | 63 +++++++++++++++++++
 .../expected/objectTypeSpreading.res.txt      | 39 ++++++++++++
 .../expected/objectTypeSpreading.res.txt      | 50 +++++++++++++++
 7 files changed, 216 insertions(+), 9 deletions(-)
 create mode 100644 tests/conversion/reason/expected/object.ml.txt
 create mode 100644 tests/parsing/errors/typexpr/expected/objectSpread.res.txt
 create mode 100644 tests/parsing/grammar/typexpr/expected/objectTypeSpreading.res.txt
 create mode 100644 tests/printer/typexpr/expected/objectTypeSpreading.res.txt

diff --git a/src/res_core.ml b/src/res_core.ml
index 9d9810c8..9475700c 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -122,8 +122,8 @@ Solution: directly use `concat`."
   let forbiddenInlineRecordDeclaration =
     "An inline record type declaration is only allowed in a variant constructor's declaration"
 
-  let ambiguousRecordSpread =
-    "The … spread is only supported for record value update and object type declaration."
+  let sameTypeSpread =
+    "You're using a ... spread without extra fields. This is the same type."
 end
 
 
@@ -3851,6 +3851,7 @@ and parseRecordOrObjectType ~attrs p =
     Parser.err p (Diagnostics.message ErrorMessages.forbiddenInlineRecordDeclaration)
   | _ -> ()
   in
+  let startFirstField = p.startPos in
   let fields =
     parseCommaDelimitedRegion
       ~grammar:Grammar.StringFieldDeclarations
@@ -3858,6 +3859,13 @@ and parseRecordOrObjectType ~attrs p =
       ~f:parseStringFieldDeclaration
       p
   in
+  let () = match fields with
+  | [Parsetree.Oinherit {ptyp_loc}] ->
+    (* {...x}, spread without extra fields *)
+    Parser.err p ~startPos:startFirstField ~endPos:ptyp_loc.loc_end
+      (Diagnostics.message ErrorMessages.sameTypeSpread)
+  | _ -> ()
+  in
   Parser.expect Rbrace p;
   let loc = mkLoc startPos p.prevEndPos in
   Ast_helper.Typ.object_ ~loc ~attrs fields closedFlag
@@ -4285,8 +4293,9 @@ and parseConstrDeclArgs p =
         let typ = parseTypExpr p in
         let () = match p.token with
         | Rbrace ->
+          (* {...x}, spread without extra fields *)
           Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
-            (Diagnostics.message ErrorMessages.ambiguousRecordSpread);
+            (Diagnostics.message ErrorMessages.sameTypeSpread);
           Parser.next p;
         | _ -> Parser.expect Comma p
         in
@@ -4705,8 +4714,9 @@ and parseRecordOrObjectDecl p =
     let typ = parseTypExpr p in
     let () = match p.token with
     | Rbrace ->
+      (* {...x}, spread without extra fields *)
       Parser.err ~startPos:dotdotdotStart ~endPos:dotdotdotEnd p
-        (Diagnostics.message ErrorMessages.ambiguousRecordSpread);
+        (Diagnostics.message ErrorMessages.sameTypeSpread);
       Parser.next p;
     | _ -> Parser.expect Comma p
     in
diff --git a/tests/conversion/reason/expected/object.ml.txt b/tests/conversion/reason/expected/object.ml.txt
new file mode 100644
index 00000000..3afee67d
--- /dev/null
+++ b/tests/conversion/reason/expected/object.ml.txt
@@ -0,0 +1,4 @@
+type hi = {"z": int}
+type u<'a> = {.. ...hi, "x": int, "y": int} as 'a
+type u1<'a> = {.. ...hi} as 'a
+type u2<'a> = {.. ...hi, ...hi, "y": int, ...hi} as 'a
diff --git a/tests/parsing/errors/other/expected/spread.res.txt b/tests/parsing/errors/other/expected/spread.res.txt
index 02e8476a..cfddb204 100644
--- a/tests/parsing/errors/other/expected/spread.res.txt
+++ b/tests/parsing/errors/other/expected/spread.res.txt
@@ -52,17 +52,57 @@ Solution: you need to pull out each field you want explicitly.
   Syntax error!
   tests/parsing/errors/other/spread.res:8:13-22
 
-  6 │ 
-  7 │ let myList = list{...x, ...y}
-  8 │ let list{...x, ...y} = myList
-  9 │ 
+   6 │ 
+   7 │ let myList = list{...x, ...y}
+   8 │ let list{...x, ...y} = myList
+   9 │ 
+  10 │ type t = {...a}
 
   List pattern matches only supports one `...` spread, at the end.
 Explanation: a list spread at the tail is efficient, but a spread in the middle would create new list[s]; out of performance concern, our pattern matching currently guarantees to never create new intermediate data.
 
+
+  Syntax error!
+  tests/parsing/errors/other/spread.res:10:11-13
+
+   8 │ let list{...x, ...y} = myList
+   9 │ 
+  10 │ type t = {...a}
+  11 │ type t = Foo({...a})
+  12 │ type t = option<foo, {...x}>
+
+  You're using a ... spread without extra fields. This is the same type.
+
+
+  Syntax error!
+  tests/parsing/errors/other/spread.res:11:15-17
+
+   9 │ 
+  10 │ type t = {...a}
+  11 │ type t = Foo({...a})
+  12 │ type t = option<foo, {...x}>
+  13 │ 
+
+  You're using a ... spread without extra fields. This is the same type.
+
+
+  Syntax error!
+  tests/parsing/errors/other/spread.res:12:23-26
+
+  10 │ type t = {...a}
+  11 │ type t = Foo({...a})
+  12 │ type t = option<foo, {...x}>
+  13 │ 
+
+  You're using a ... spread without extra fields. This is the same type.
+
 let arr = [|x;y|]
 let [|arr;_|] = [|1;2;3|]
 let record = { x with y }
 let { x; y } = myRecord
 let myList = x :: y
-let x::y = myList
\ No newline at end of file
+let x::y = myList
+type nonrec t = < a  > 
+type nonrec t =
+  | Foo of < a  >  
+type nonrec t = (foo, < x  > ) option
\ No newline at end of file
diff --git a/tests/parsing/errors/other/spread.res b/tests/parsing/errors/other/spread.res
index 5ed52108..e30a6129 100644
--- a/tests/parsing/errors/other/spread.res
+++ b/tests/parsing/errors/other/spread.res
@@ -9,3 +9,4 @@ let list{...x, ...y} = myList
 
 type t = {...a}
 type t = Foo({...a})
+type t = option<foo, {...x}>
diff --git a/tests/parsing/errors/typexpr/expected/objectSpread.res.txt b/tests/parsing/errors/typexpr/expected/objectSpread.res.txt
new file mode 100644
index 00000000..373996a4
--- /dev/null
+++ b/tests/parsing/errors/typexpr/expected/objectSpread.res.txt
@@ -0,0 +1,63 @@
+
+  Syntax error!
+  tests/parsing/errors/typexpr/objectSpread.res:1:11-13
+
+  1 │ type u = {...a, u: int}
+  2 │ 
+  3 │ type u = private {...a, u: int}
+
+  A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does.
+
+
+  Syntax error!
+  tests/parsing/errors/typexpr/objectSpread.res:3:19-21
+
+  1 │ type u = {...a, u: int}
+  2 │ 
+  3 │ type u = private {...a, u: int}
+  4 │ 
+  5 │ type x = Type({...a, u: int})
+
+  A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does.
+
+
+  Syntax error!
+  tests/parsing/errors/typexpr/objectSpread.res:5:16-18
+
+  3 │ type u = private {...a, u: int}
+  4 │ 
+  5 │ type x = Type({...a, u: int})
+  6 │ 
+  7 │ type u = {...a, "u": int, v: int}
+
+  A record type declaration doesn't support the ... spread. Only an object (with quoted field names) does.
+
+
+  Syntax error!
+  tests/parsing/errors/typexpr/objectSpread.res:7:27
+
+  5 │ type x = Type({...a, u: int})
+  6 │ 
+  7 │ type u = {...a, "u": int, v: int}
+  8 │ 
+  9 │ let f = (x: {a: int, b: int}) => ()
+
+  An object type declaration needs quoted field names. Did you mean "v"?
+
+
+  Syntax error!
+  tests/parsing/errors/typexpr/objectSpread.res:9:14
+
+   7 │ type u = {...a, "u": int, v: int}
+   8 │ 
+   9 │ let f = (x: {a: int, b: int}) => ()
+  10 │ 
+
+  An inline record type declaration is only allowed in a variant constructor's declaration
+
+type nonrec u = < a ;u: int   > 
+type nonrec u = private < a ;u: int   > 
+type nonrec x =
+  | Type of < a ;u: int   >  
+type nonrec u = < a ;u: int  ;v: int   > 
+let f (x : < a: int  ;b: int   > ) = ()
\ No newline at end of file
diff --git a/tests/parsing/grammar/typexpr/expected/objectTypeSpreading.res.txt b/tests/parsing/grammar/typexpr/expected/objectTypeSpreading.res.txt
new file mode 100644
index 00000000..4ac552a2
--- /dev/null
+++ b/tests/parsing/grammar/typexpr/expected/objectTypeSpreading.res.txt
@@ -0,0 +1,39 @@
+type nonrec a = < x: int   > 
+type nonrec u = < a ;u: int   > 
+type nonrec v = < v: int  ;a  > 
+type nonrec w = < j: int  ;a ;k: int  ;v  > 
+type nonrec t = < a ;u: int   >  as 'a
+type nonrec t = < a ;u: int   >  -> unit
+type nonrec t = (< a ;u: int   >  as 'a) -> unit
+type nonrec t = < a ;u: int   >  -> < a ;v: int   >  -> unit
+type nonrec user = < name: string   > 
+let (steve : < user ;age: int   > ) = [%obj { name = "Steve"; age = 30 }]
+let steve = ([%obj { name = "Steve"; age = 30 }] : < user ;age: int   > )
+let steve = ((([%obj { name = "Steve"; age = 30 }] : < user ;age: int   > ))
+  [@ns.braces ])
+let printFullUser (steve : < user ;age: int   > ) = Js.log steve
+let printFullUser ~user:(((user : < user ;age: int   > ))[@ns.namedArgLoc ]) 
+  = Js.log steve
+let printFullUser ~user:(((user : < user ;age: int   > ))[@ns.namedArgLoc ]) 
+  = Js.log steve
+let printFullUser ?user:(((user)[@ns.namedArgLoc ])=
+  (steve : < user ;age: int   > ))  = Js.log steve
+external steve : < user ;age: int   >  = "steve"[@@val ]
+let makeCeoOf30yearsOld name =
+  ([%obj { name; age = 30 }] : < user ;age: int   > )
+type nonrec optionalUser = < user ;age: int   >  option
+type nonrec optionalTupleUser =
+  (< user ;age: int   >  * < user ;age: int   > ) option
+type nonrec constrUser =
+  (< user ;age: int   > , < user ;age: int   > ) myTypeConstructor
+type nonrec taggedUser =
+  | User of < user ;age: int   >  
+  | Ceo of < user ;age: int  ;direction: bool   >  *
+  < salary ;taxFraud: bool   >  
+type nonrec polyTaggedUser = [ `User of < user ;age: int   >  ]
+type nonrec polyTaggedUser2 =
+  [ `User of < user ;age: int   >  
+  | `Ceo of
+      (< user ;age: int  ;direction: bool   >  *
+        < salary ;taxFraud: bool   > )
+      ]
\ No newline at end of file
diff --git a/tests/printer/typexpr/expected/objectTypeSpreading.res.txt b/tests/printer/typexpr/expected/objectTypeSpreading.res.txt
new file mode 100644
index 00000000..81446937
--- /dev/null
+++ b/tests/printer/typexpr/expected/objectTypeSpreading.res.txt
@@ -0,0 +1,50 @@
+type a = {"x": int}
+type u = {...a, "u": int}
+type v = {"v": int, ...a}
+type w = {"j": int, ...a, "k": int, ...v}
+
+type t = {...a, "u": int} as 'a
+type t = {...a, "u": int} => unit
+type t = ({...a, "u": int} as 'a) => unit
+type t = ({...a, "u": int}, {...a, "v": int}) => unit
+
+type user = {"name": string}
+
+let steve: {...user, "age": int} = {"name": "Steve", "age": 30}
+let steve = ({"name": "Steve", "age": 30}: {...user, "age": int})
+let steve = {({"name": "Steve", "age": 30}: {...user, "age": int})}
+
+let printFullUser = (steve: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user: {...user, "age": int}) => Js.log(steve)
+let printFullUser = (~user=steve: {...user, "age": int}) => Js.log(steve)
+
+@val
+external steve: {...user, "age": int} = "steve"
+
+let makeCeoOf30yearsOld = (name): {...user, "age": int} => {"name": name, "age": 30}
+
+type optionalUser = option<{...user, "age": int}>
+type optionalTupleUser = option<({...user, "age": int}, {...user, "age": int})>
+type constrUser = myTypeConstructor<{...user, "age": int}, {...user, "age": int}>
+
+type taggedUser =
+  | User({...user, "age": int})
+  | Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool})
+
+type polyTaggedUser = [#User({...user, "age": int})]
+type polyTaggedUser2 = [
+  | #User({...user, "age": int})
+  | #Ceo({...user, "age": int, "direction": bool}, {...salary, "taxFraud": bool})
+]
+
+// notice .. and ..., they should have a space
+type u<'a> = {.. ...hi} as 'a
+type u<'a> = {.. ...hi, "superLongFieldName": string, "superLongFieldName22222222222": int} as 'a
+type u<'a> = {..
+  ...hi,
+  "superLongFieldName": string,
+  ...hi,
+  "superLongFieldName22222222222": int,
+  ...hi,
+} as 'a

From 171c35eb60af22f7b18f36a49971c81c2331c547 Mon Sep 17 00:00:00 2001
From: Iwan <mvalcke@hubspot.com>
Date: Thu, 25 Mar 2021 19:20:09 +0100
Subject: [PATCH 8/8] Update object method parsing and printer for ReScript 9

Fixes https://github.com/rescript-lang/syntax/issues/311

`obj["say"]` was currently parsed as `obj##say` (Pexp_apply with ##)
We now parse this straight into `obj#say`(Pexp_send)
---
 src/res_ast_conversion.ml                     | 24 ++++++++----------
 src/res_core.ml                               |  4 +--
 src/res_printer.ml                            | 22 ++++++++++++++--
 .../reason/__snapshots__/render.spec.js.snap  | 11 ++++++++
 tests/conversion/reason/jsObject.re           | 12 +++++++++
 .../other/__snapshots__/parse.spec.js.snap    | 22 ++++++++++++----
 .../other/expected/breadcrumbs170.res.txt     |  2 +-
 .../__snapshots__/parse.spec.js.snap          | 25 +++++++++----------
 .../grammar/expressions/expected/jsx.res.txt  | 11 ++++----
 .../expressions/expected/primary.res.txt      | 14 +++++------
 10 files changed, 97 insertions(+), 50 deletions(-)

diff --git a/src/res_ast_conversion.ml b/src/res_ast_conversion.ml
index 9aacff35..aea8c210 100644
--- a/src/res_ast_conversion.ml
+++ b/src/res_ast_conversion.ml
@@ -421,7 +421,7 @@ let normalize =
                   pexp_attributes = [];
                   pexp_desc = Pexp_ident (Location.mknoloc (Longident.Lident "x"))
                 },
-                (default_mapper.cases mapper cases)
+                (mapper.cases mapper cases)
               )
 
             }
@@ -435,21 +435,19 @@ let normalize =
         {
           pexp_loc = expr.pexp_loc;
           pexp_attributes = expr.pexp_attributes;
-          pexp_desc = Pexp_field (operand, (Location.mknoloc (Longident.Lident "contents")))
+          pexp_desc = Pexp_field (mapper.expr mapper operand, (Location.mknoloc (Longident.Lident "contents")))
         }
       | Pexp_apply (
-          {pexp_desc = Pexp_ident {txt = Longident.Lident "##"}} as op,
-          [Asttypes.Nolabel, lhs; Nolabel, ({pexp_desc = Pexp_constant (Pconst_string (txt, None))} as stringExpr)]
+          {pexp_desc = Pexp_ident {txt = Longident.Lident "##"}},
+          [
+            Asttypes.Nolabel, lhs; Nolabel,
+            ({pexp_desc = Pexp_constant (Pconst_string (txt, None)) | (Pexp_ident ({txt = Longident.Lident txt})); pexp_loc = labelLoc})]
         ) ->
-        let ident = {
-          Parsetree.pexp_loc = stringExpr.pexp_loc;
-          pexp_attributes = [];
-          pexp_desc = Pexp_ident (Location.mkloc (Longident.Lident txt) stringExpr.pexp_loc)
-        } in
+        let label = Location.mkloc txt labelLoc in
         {
           pexp_loc = expr.pexp_loc;
           pexp_attributes = expr.pexp_attributes;
-          pexp_desc = Pexp_apply (op, [Asttypes.Nolabel, lhs; Nolabel, ident])
+          pexp_desc = Pexp_send (mapper.expr mapper lhs, label)
         }
       | Pexp_match (
           condition,
@@ -461,9 +459,9 @@ let normalize =
         let ternaryMarker = (Location.mknoloc "ns.ternary", Parsetree.PStr []) in
         {Parsetree.pexp_loc = expr.pexp_loc;
           pexp_desc = Pexp_ifthenelse (
-            default_mapper.expr mapper condition,
-            default_mapper.expr mapper thenExpr,
-            (Some (default_mapper.expr mapper elseExpr))
+            mapper.expr mapper condition,
+            mapper.expr mapper thenExpr,
+            (Some (mapper.expr mapper elseExpr))
           );
           pexp_attributes = ternaryMarker::expr.pexp_attributes;
         }
diff --git a/src/res_core.ml b/src/res_core.ml
index 9475700c..21e191e0 100644
--- a/src/res_core.ml
+++ b/src/res_core.ml
@@ -1955,9 +1955,7 @@ and parseBracketAccess p expr startPos =
     let e =
       let identLoc = mkLoc stringStart stringEnd in
       let loc = mkLoc lbracket rbracket in
-      Ast_helper.Exp.apply ~loc
-      (Ast_helper.Exp.ident ~loc (Location.mkloc (Longident.Lident "##") loc))
-      [Nolabel, expr; Nolabel, (Ast_helper.Exp.ident ~loc:identLoc (Location.mkloc (Longident.Lident s) identLoc))]
+      Ast_helper.Exp.send ~loc expr (Location.mkloc s identLoc)
     in
     let e = parsePrimaryExpr ~operand:e p in
     let equalStart = p.startPos in
diff --git a/src/res_printer.ml b/src/res_printer.ml
index 83ea99d8..225230ba 100644
--- a/src/res_printer.ml
+++ b/src/res_printer.ml
@@ -3137,8 +3137,26 @@ and printExpression (e : Parsetree.expression) cmtTbl =
       Doc.concat [Doc.text ": "; printTypExpr typ1 cmtTbl]
     in
     Doc.concat [Doc.lparen; docExpr; ofType; Doc.text " :> "; docTyp; Doc.rparen]
-  | Pexp_send _ ->
-    Doc.text "Pexp_send not impemented in printer"
+  | Pexp_send (parentExpr, label) ->
+    let parentDoc =
+      let doc = printExpressionWithComments parentExpr cmtTbl in
+      match Parens.unaryExprOperand parentExpr with
+      | Parens.Parenthesized -> addParens doc
+      | Braced braces  -> printBraces doc parentExpr braces
+      | Nothing -> doc
+    in
+    let member =
+      let memberDoc = printComments (Doc.text label.txt) cmtTbl label.loc in
+      Doc.concat [Doc.text "\""; memberDoc; Doc.text "\""]
+    in
+    Doc.group (
+      Doc.concat [
+        parentDoc;
+        Doc.lbracket;
+        member;
+        Doc.rbracket;
+      ]
+    )
   | Pexp_new _ ->
     Doc.text "Pexp_new not impemented in printer"
   | Pexp_setinstvar _ ->
diff --git a/tests/conversion/reason/__snapshots__/render.spec.js.snap b/tests/conversion/reason/__snapshots__/render.spec.js.snap
index 113140cb..558acefa 100644
--- a/tests/conversion/reason/__snapshots__/render.spec.js.snap
+++ b/tests/conversion/reason/__snapshots__/render.spec.js.snap
@@ -1285,6 +1285,17 @@ type propField<'a> = Js.nullable<{..} as 'a>
 type propField<'a> = {\\"a\\": b}
 type propField<'a> = {..\\"a\\": b}
 type propField<'a> = {\\"a\\": {\\"b\\": c}}
+
+user[\\"address\\"]
+user[\\"address\\"][\\"street\\"]
+user[\\"address\\"][\\"street\\"][\\"log\\"]
+
+user[\\"address\\"] = \\"Avenue 1\\"
+user[\\"address\\"][\\"street\\"] = \\"Avenue\\"
+user[\\"address\\"][\\"street\\"][\\"number\\"] = \\"1\\"
+
+school[\\"print\\"](direction[\\"name\\"], studentHead[\\"name\\"])
+city[\\"getSchool\\"]()[\\"print\\"](direction[\\"name\\"], studentHead[\\"name\\"])
 "
 `;
 
diff --git a/tests/conversion/reason/jsObject.re b/tests/conversion/reason/jsObject.re
index 48aa165b..9d2eeefe 100644
--- a/tests/conversion/reason/jsObject.re
+++ b/tests/conversion/reason/jsObject.re
@@ -13,3 +13,15 @@ type propField('a) = Js.nullable(Js.t({..} as 'a))
 type propField('a) = {. "a": b}
 type propField('a) = {.. "a": b}
 type propField('a) = Js.t(Js.t({. "a": Js.t({. "b": c})}))
+
+user##address;
+user##address##street;
+user##address##street##log;
+
+user##address #= "Avenue 1";
+user##address##street #= "Avenue" ;
+user##address##street##number #= "1";
+
+school##print(direction##name, studentHead##name);
+(city##getSchool())##print(direction##name, studentHead##name);
+
diff --git a/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap b/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap
index 6dcaf4b1..c1e56b30 100644
--- a/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap
+++ b/tests/parsing/errors/other/__snapshots__/parse.spec.js.snap
@@ -3,7 +3,7 @@
 exports[`breadcrumbs170.res 1`] = `
 "=====Parsetree==========================================
 let l = (Some [1; 2; 3]) |> Obj.magic
-module M = struct ;;match l with | None -> [] | Some l -> l ## prop end
+module M = struct ;;match l with | None -> [] | Some l -> l#prop end
 ;;from
 ;;now
 ;;on
@@ -169,6 +169,7 @@ let x::y = myList
 type nonrec t = < a  > 
 type nonrec t =
   | Foo of < a  >  
+type nonrec t = (foo, < x  > ) option
 =====Errors=============================================
 
   Syntax error!
@@ -235,9 +236,9 @@ Explanation: a list spread at the tail is efficient, but a spread in the middle
    9 │ 
   10 │ type t = {...a}
   11 │ type t = Foo({...a})
-  12 │ 
+  12 │ type t = option<foo, {...x}>
 
-  The … spread is only supported for record value update and object type declaration.
+  You're using a ... spread without extra fields. This is the same type.
 
 
   Syntax error!
@@ -245,9 +246,20 @@ Explanation: a list spread at the tail is efficient, but a spread in the middle
    9 │ 
   10 │ type t = {...a}
   11 │ type t = Foo({...a})
-  12 │ 
+  12 │ type t = option<foo, {...x}>
+  13 │ 
 
-  The … spread is only supported for record value update and object type declaration.
+  You're using a ... spread without extra fields. This is the same type.
+
+
+  Syntax error!
+  parsing/errors/other/spread.res:12:23-26
+  10 │ type t = {...a}
+  11 │ type t = Foo({...a})
+  12 │ type t = option<foo, {...x}>
+  13 │ 
+
+  You're using a ... spread without extra fields. This is the same type.
 
 
 ========================================================"
diff --git a/tests/parsing/errors/other/expected/breadcrumbs170.res.txt b/tests/parsing/errors/other/expected/breadcrumbs170.res.txt
index 49784c45..8f950a16 100644
--- a/tests/parsing/errors/other/expected/breadcrumbs170.res.txt
+++ b/tests/parsing/errors/other/expected/breadcrumbs170.res.txt
@@ -11,7 +11,7 @@
   I'm not sure what to parse here when looking at "}".
 
 let l = (Some [1; 2; 3]) |> Obj.magic
-module M = struct ;;match l with | None -> [] | Some l -> l ## prop end
+module M = struct ;;match l with | None -> [] | Some l -> l#prop end
 ;;from
 ;;now
 ;;on
diff --git a/tests/parsing/grammar/expressions/__snapshots__/parse.spec.js.snap b/tests/parsing/grammar/expressions/__snapshots__/parse.spec.js.snap
index 9f564423..72df3fa9 100644
--- a/tests/parsing/grammar/expressions/__snapshots__/parse.spec.js.snap
+++ b/tests/parsing/grammar/expressions/__snapshots__/parse.spec.js.snap
@@ -778,10 +778,10 @@ let icon =
   [@JSX ])
 let _ =
   ((MessengerSharedPhotosAlbumViewPhotoReact.createElement
-      ?ref:((if (foo ## bar) == baz
+      ?ref:((if foo#bar == baz
              then Some (foooooooooooooooooooooooo setRefChild)
              else None)[@ns.namedArgLoc ][@ns.ternary ])
-      ~key:((node ## legacy_attachment_id)[@ns.namedArgLoc ]) ~children:[] ())
+      ~key:((node#legacy_attachment_id)[@ns.namedArgLoc ]) ~children:[] ())
   [@JSX ])
 let _ = ((Foo.createElement ~bar:((bar)[@ns.namedArgLoc ]) ~children:[] ())
   [@JSX ])
@@ -792,7 +792,7 @@ let _ =
   [@JSX ])
 let x = ((div ~children:[] ())[@JSX ])
 let _ = ((div ~asd:((1)[@ns.namedArgLoc ]) ~children:[] ())[@JSX ])
-;;(foo ## bar) #= ((bar ~children:[] ())[@JSX ])
+;;foo#bar #= ((bar ~children:[] ())[@JSX ])
 ;;foo #= ((bar ~children:[] ())[@JSX ])
 ;;foo #= ((bar ~children:[] ())[@JSX ])
 let x = [|((div ~children:[] ())[@JSX ])|]
@@ -1078,12 +1078,11 @@ let _ =
                 [@ns.braces ])] ())
   [@JSX ])
 let _ =
-  ((View.createElement ~style:((styles ## backgroundImageWrapper)
+  ((View.createElement ~style:((styles#backgroundImageWrapper)
       [@ns.namedArgLoc ])
       ~children:[(((let uri = \\"/images/header-background.png\\" in
                     ((Image.createElement ~resizeMode:((Contain)
-                        [@ns.namedArgLoc ])
-                        ~style:((styles ## backgroundImage)
+                        [@ns.namedArgLoc ]) ~style:((styles#backgroundImage)
                         [@ns.namedArgLoc ]) ~uri:((uri)[@ns.namedArgLoc ])
                         ~children:[] ())
                       [@JSX ])))
@@ -1215,13 +1214,13 @@ let x = (arr.((x : int))).((y : int))
     [@ns.namedArgLoc ]) ~b:((bArg)[@ns.namedArgLoc ]) ?c:((c)
     [@ns.namedArgLoc ]) ?d:((expr)[@ns.namedArgLoc ])
 ;;f ~a:(((x : int))[@ns.namedArgLoc ]) ?b:(((y : int))[@ns.namedArgLoc ])
-;;connection ## platformId
-;;((connection ## left) ## account) ## accountName
-;;(john ## age) #= 99
-;;((john ## son) ## age) #= ((steve ## age) - 5)
-;;(dict ## 
-) #= abc
-;;(dict ## \\") #= (dict2 ## \\")"
+;;connection#platformId
+;;((connection#left)#account)#accountName
+;;john#age #= 99
+;;(john#son)#age #= (steve#age - 5)
+;;dict#
+ #= abc
+;;dict#\\" #= dict2#\\""
 `;
 
 exports[`record.res 1`] = `
diff --git a/tests/parsing/grammar/expressions/expected/jsx.res.txt b/tests/parsing/grammar/expressions/expected/jsx.res.txt
index 1b394e2f..0e5836ba 100644
--- a/tests/parsing/grammar/expressions/expected/jsx.res.txt
+++ b/tests/parsing/grammar/expressions/expected/jsx.res.txt
@@ -220,10 +220,10 @@ let icon =
   [@JSX ])
 let _ =
   ((MessengerSharedPhotosAlbumViewPhotoReact.createElement
-      ?ref:((if (foo ## bar) == baz
+      ?ref:((if foo#bar == baz
              then Some (foooooooooooooooooooooooo setRefChild)
              else None)[@ns.namedArgLoc ][@ns.ternary ])
-      ~key:((node ## legacy_attachment_id)[@ns.namedArgLoc ]) ~children:[] ())
+      ~key:((node#legacy_attachment_id)[@ns.namedArgLoc ]) ~children:[] ())
   [@JSX ])
 let _ = ((Foo.createElement ~bar:((bar)[@ns.namedArgLoc ]) ~children:[] ())
   [@JSX ])
@@ -234,7 +234,7 @@ let _ =
   [@JSX ])
 let x = ((div ~children:[] ())[@JSX ])
 let _ = ((div ~asd:((1)[@ns.namedArgLoc ]) ~children:[] ())[@JSX ])
-;;(foo ## bar) #= ((bar ~children:[] ())[@JSX ])
+;;foo#bar #= ((bar ~children:[] ())[@JSX ])
 ;;foo #= ((bar ~children:[] ())[@JSX ])
 ;;foo #= ((bar ~children:[] ())[@JSX ])
 let x = [|((div ~children:[] ())[@JSX ])|]
@@ -520,12 +520,11 @@ let _ =
                 [@ns.braces ])] ())
   [@JSX ])
 let _ =
-  ((View.createElement ~style:((styles ## backgroundImageWrapper)
+  ((View.createElement ~style:((styles#backgroundImageWrapper)
       [@ns.namedArgLoc ])
       ~children:[(((let uri = "/images/header-background.png" in
                     ((Image.createElement ~resizeMode:((Contain)
-                        [@ns.namedArgLoc ])
-                        ~style:((styles ## backgroundImage)
+                        [@ns.namedArgLoc ]) ~style:((styles#backgroundImage)
                         [@ns.namedArgLoc ]) ~uri:((uri)[@ns.namedArgLoc ])
                         ~children:[] ())
                       [@JSX ])))
diff --git a/tests/parsing/grammar/expressions/expected/primary.res.txt b/tests/parsing/grammar/expressions/expected/primary.res.txt
index 8584645c..52c22acc 100644
--- a/tests/parsing/grammar/expressions/expected/primary.res.txt
+++ b/tests/parsing/grammar/expressions/expected/primary.res.txt
@@ -27,10 +27,10 @@ let x = (arr.((x : int))).((y : int))
     [@ns.namedArgLoc ]) ~b:((bArg)[@ns.namedArgLoc ]) ?c:((c)
     [@ns.namedArgLoc ]) ?d:((expr)[@ns.namedArgLoc ])
 ;;f ~a:(((x : int))[@ns.namedArgLoc ]) ?b:(((y : int))[@ns.namedArgLoc ])
-;;connection ## platformId
-;;((connection ## left) ## account) ## accountName
-;;(john ## age) #= 99
-;;((john ## son) ## age) #= ((steve ## age) - 5)
-;;(dict ## 
-) #= abc
-;;(dict ## ") #= (dict2 ## ")
\ No newline at end of file
+;;connection#platformId
+;;((connection#left)#account)#accountName
+;;john#age #= 99
+;;(john#son)#age #= (steve#age - 5)
+;;dict#
+ #= abc
+;;dict#" #= dict2#"
\ No newline at end of file