Add extra test cases for printing of comments inside if-let.

Author: Iwan

src/napkin_comments_table.ml

@@ -137,3 +137,5 @@ val rewriteUnderscoreApply: Parsetree.expression -> Parsetree.expression
 
 (* (__x) => f(a, __x, c) -----> f(a, _, c)  *)
 val isUnderscoreApplySugar: Parsetree.expression -> bool
+
+val hasIfLetAttribute: Parsetree.attributes -> bool

src/napkin_parsetree_viewer.ml

@@ -2393,12 +2393,19 @@ and printIfChain pexp_attributes ifs elseExpr cmtTbl =
             printExpressionBlock ~braces:true thenExpr cmtTbl;
           ]
         | IfLet (pattern, conditionExpr) ->
+          let conditionDoc =
+            let doc = printExpressionWithComments conditionExpr cmtTbl in
+            match Parens.expr conditionExpr with
+            | Parens.Parenthesized -> addParens doc
+            | Braced braces -> printBraces doc conditionExpr braces
+            | Nothing -> doc
+          in
           Doc.concat [
             ifTxt;
             Doc.text "let ";
             printPattern pattern cmtTbl;
             Doc.text " = ";
-            printExpressionWithComments conditionExpr cmtTbl;
+            conditionDoc;
             Doc.space;
             printExpressionBlock ~braces:true thenExpr cmtTbl;
           ]

src/napkin_parsetree_viewer.mli

@@ -913,6 +913,34 @@ comment
 "
 `;
 
+exports[`ifLet.res 1`] = `
+"if let /* c0 */ /* c1 */ Some(
+  /* c2 */ x /* c3 */,
+) /* c4 */ = /* c5 */ makeOpt() /* c6 */ {
+  /* c7 */ foo() /* c8 */
+} else {
+  /* c9 */ bar() /* c10 */
+}
+
+let getZ2 = nested =>
+  if let /* c-4 */ Some(point) /* c-3 */ = /* c-2 */ nested.origin /* c-1 */ {
+    if let /* c0 */ Some(/* c1 */ z /* c2 */) = /* c3 */ point.z /* c4 */ {
+      let pi /* inside */ = 3.13 *. point.z // trailing1
+      let e /* inside1 */ = 42.3 // trailing2
+      pi *. e // trailing3
+    } else {
+      let pi /* inside2 */ = 3.13 // trailing4
+      let e /* inside3 */ = 42.3 // trailing5
+      pi *. e // trailing6
+    }
+  } else {
+    let pi /* inside4 */ = 3.13 // trailing7
+    let e /* inside5 */ = 42.3 // trailing8
+    pi *. e // trailing9
+  }
+"
+`;
+
 exports[`interfaceWithOneSingleComment.nsi 1`] = `
 "// retain this comment
 "

src/napkin_printer.ml

@@ -0,0 +1,22 @@
+if /* c0 */ let /* c1 */ Some(/* c2 */ x /* c3 */) /* c4 */ = /* c5 */ makeOpt() /* c6 */ {
+  /* c7 */ foo() /* c8 */
+} else {
+  /* c9 */ bar() /* c10 */
+}
+
+let getZ2 = nested =>
+  if let /* c-4 */ Some(point) /* c-3 */ =  /* c-2 */ nested.origin  /* c-1 */ {
+    if let /* c0 */ Some( /* c1 */ z /* c2 */ ) =/* c3 */ point.z /* c4 */ {
+      let pi /* inside */ = 3.13 *. point.z // trailing1
+      let e /* inside1 */= 42.3 // trailing2
+      pi *. e // trailing3
+    } else {
+      let pi /* inside2 */= 3.13 // trailing4
+      let e /* inside3 */= 42.3 // trailing5
+      pi *. e // trailing6
+    }
+  } else {
+    let pi /* inside4 */ = 3.13 // trailing7
+    let e /* inside5 */ = 42.3 // trailing8
+    pi *. e // trailing9
+  }

tests/printer/comments/__snapshots__/render.spec.js.snap

@@ -2387,6 +2387,13 @@ let a = b
     } else {
       2
     }
+
+// print parens correct
+if let Some(x) = (3: option<int>) {
+  (x: int)
+} else {
+  (20: int)
+}
 "
 `;
 

tests/printer/comments/ifLet.res

@@ -215,3 +215,10 @@ let a = b
     } else {
       2
     }
+
+// print parens correct
+if let Some(x) = (3: option<int>) {
+  (x: int)
+} else {
+  (20: int)
+}