feat: handle paths via source_file instead of cmt_file

Author: Bushuo

jscomp/gentype/GenTypeMain.ml

@@ -136,8 +136,6 @@ let processCmtFile cmt =
   if !Debug.basic then Log_.item "Cmt %s\n" cmt;
   let cmtFile = cmt |> Paths.getCmtFile in
   if cmtFile <> "" then
-    let outputFile = cmt |> Paths.getOutputFile ~config in
-    let outputFileRelative = cmt |> Paths.getOutputFileRelative ~config in
     let fileName = cmt |> Paths.getModuleName in
     let isInterface = Filename.check_suffix cmtFile ".cmti" in
     let inputCMT, hasGenTypeAnnotations = readInputCmt isInterface cmtFile in
@@ -151,6 +149,10 @@ let processCmtFile cmt =
         | true -> ".resi"
         | false -> ".res")
     in
+    let outputFile = sourceFile |> Paths.getOutputFile ~config in
+    let outputFileRelative =
+      sourceFile |> Paths.getOutputFileRelative ~config
+    in
     let resolver =
       ModuleResolver.createLazyResolver ~config ~extensions:[".res"; ".shim.ts"]
         ~excludeFile:(fun fname ->

jscomp/gentype/Paths.ml

@@ -28,17 +28,42 @@ let findNameSpace cmt =
   cmt |> Filename.basename |> (Filename.chop_extension [@doesNotRaise])
   |> keepAfterDash
 
-let getOutputFileRelative ~config cmt =
-  (cmt |> handleNamespace) ^ ModuleExtension.tsInputFileSuffix ~config
+let remove_project_root_from_absolute_path ~(config : Config.t) source_path =
+  let i = String.length config.projectRoot + 1 in
+  let n = String.length source_path - i in
+  (String.sub source_path i n [@doesNotRaise])
 
-let getOutputFile ~(config : Config.t) cmt =
-  Filename.concat config.projectRoot (getOutputFileRelative ~config cmt)
+let getOutputFileRelative ~config source_path =
+  if Filename.is_relative source_path then
+    (source_path |> handleNamespace) ^ ModuleExtension.tsInputFileSuffix ~config
+  else
+    let relative_path =
+      remove_project_root_from_absolute_path ~config source_path
+    in
+    (relative_path |> handleNamespace)
+    ^ ModuleExtension.tsInputFileSuffix ~config
+
+let getOutputFile ~(config : Config.t) sourcePath =
+  if Filename.is_relative sourcePath then
+    (* assuming a relative path from the project root *)
+    Filename.concat config.projectRoot
+      (getOutputFileRelative ~config sourcePath)
+  else
+    (* we want to place the output beside the source file *)
+    let relative_path =
+      remove_project_root_from_absolute_path ~config sourcePath
+    in
+    Filename.concat config.projectRoot
+      (getOutputFileRelative ~config relative_path)
 
 let getModuleName cmt =
   cmt |> handleNamespace |> Filename.basename |> ModuleName.fromStringUnsafe
 
 let getCmtFile cmt =
-  let pathCmt = Filename.concat (Sys.getcwd ()) cmt in
+  let pathCmt =
+    if Filename.is_relative cmt then Filename.concat (Sys.getcwd ()) cmt
+    else cmt
+  in
   let cmtFile =
     if Filename.check_suffix pathCmt ".cmt" then
       let pathCmtLowerCase =