relax requirement of files being in a ReScript project for formatting

CHANGELOG.md

@@ -1,4 +1,5 @@
 ## master
+
 - Fix issue where using paths of the form `./something` would show multiple copies of the same file in vscode.
 - When hovering on a field access, show the instantiated type of the field.
 - Support autocomplete for objects from another module `M.x[...`.
@@ -8,6 +9,7 @@
 - Report "Fatal error" when it happens in the compiler log (e.g. a make function with type annotation) and don't crash the extension.
 - Fix issue in functions the form "~foo as name" where the location would only cover "ame".
 - Extend the command to create an interface file, to support components and ReScript decorators used in bindings.
+- Enable formatting files without needing the file to be in an actual ReScript project.
 - New feature: Show Outline which was previously disabled.
 
 ## 1.2.1

analysis/src/Cli.ml

@@ -56,6 +56,10 @@ Options:
 
     ./rescript-editor-analysis.exe createInterface src/MyFile.res lib/bs/src/MyFile.cmi
 
+  format: print to stdout the formatted version of the provided file
+
+    ./rescript-editor-analysis.exe format src/MyFile.res
+
   test: run tests specified by special comments in file src/MyFile.res
 
     ./rescript-editor-analysis.exe test src/src/MyFile.res
@@ -86,6 +90,8 @@ let main () =
   | [_; "createInterface"; path; cmiFile] ->
     Printf.printf "\"%s\""
       (Json.escape (CreateInterface.command ~path ~cmiFile))
+  | [_; "format"; path] ->
+    Printf.printf "\"%s\"" (Json.escape (Commands.format ~path))
   | [_; "test"; path] -> Commands.test ~path
   | args when List.mem "-h" args || List.mem "--help" args -> prerr_endline help
   | _ ->

analysis/src/Commands.ml

@@ -210,6 +210,24 @@ let rename ~path ~line ~col ~newName =
   in
   print_endline result
 
+let format ~path =
+  if Filename.check_suffix path ".res" then
+    let {Res_driver.parsetree = structure; comments; diagnostics} =
+      Res_driver.parsingEngine.parseImplementation ~forPrinter:true
+        ~filename:path
+    in
+    if List.length diagnostics > 0 then ""
+    else
+      Res_printer.printImplementation !Res_cli.ResClflags.width structure
+        comments
+  else if Filename.check_suffix path ".resi" then
+    let {Res_driver.parsetree = signature; comments; diagnostics} =
+      Res_driver.parsingEngine.parseInterface ~forPrinter:true ~filename:path
+    in
+    if List.length diagnostics > 0 then ""
+    else Res_printer.printInterface !Res_cli.ResClflags.width signature comments
+  else ""
+
 let test ~path =
   Uri2.stripPath := true;
   match Files.readFile path with

server/src/server.ts

@@ -463,49 +463,37 @@ function format(msg: p.RequestMessage): Array<m.Message> {
     // See comment on findBscNativeDirOfFile for why we need
     // to recursively search for bsc.exe upward
     let bscNativePath = utils.findBscNativeOfFile(filePath);
-    if (bscNativePath === null) {
-      let params: p.ShowMessageParams = {
-        type: p.MessageType.Error,
-        message: `Cannot find a nearby bsc.exe in rescript or bs-platform. It's needed for formatting.`,
-      };
-      let response: m.NotificationMessage = {
+
+    // code will always be defined here, even though technically it can be undefined
+    let code = getOpenedFileContent(params.textDocument.uri);
+    let formattedResult = utils.formatCode(
+      code,
+      bscNativePath,
+      extension === c.resiExt
+    );
+    if (formattedResult.kind === "success") {
+      let max = code.length;
+      let result: p.TextEdit[] = [
+        {
+          range: {
+            start: { line: 0, character: 0 },
+            end: { line: max, character: max },
+          },
+          newText: formattedResult.result,
+        },
+      ];
+      let response: m.ResponseMessage = {
         jsonrpc: c.jsonrpcVersion,
-        method: "window/showMessage",
-        params: params,
+        id: msg.id,
+        result: result,
       };
-      return [fakeSuccessResponse, response];
+      return [response];
     } else {
-      // code will always be defined here, even though technically it can be undefined
-      let code = getOpenedFileContent(params.textDocument.uri);
-      let formattedResult = utils.formatUsingValidBscNativePath(
-        code,
-        bscNativePath,
-        extension === c.resiExt
-      );
-      if (formattedResult.kind === "success") {
-        let max = code.length;
-        let result: p.TextEdit[] = [
-          {
-            range: {
-              start: { line: 0, character: 0 },
-              end: { line: max, character: max },
-            },
-            newText: formattedResult.result,
-          },
-        ];
-        let response: m.ResponseMessage = {
-          jsonrpc: c.jsonrpcVersion,
-          id: msg.id,
-          result: result,
-        };
-        return [response];
-      } else {
-        // let the diagnostics logic display the updated syntax errors,
-        // from the build.
-        // Again, not sending the actual errors. See fakeSuccessResponse
-        // above for explanation
-        return [fakeSuccessResponse];
-      }
+      // let the diagnostics logic display the updated syntax errors,
+      // from the build.
+      // Again, not sending the actual errors. See fakeSuccessResponse
+      // above for explanation
+      return [fakeSuccessResponse];
     }
   }
 }

server/src/utils.ts

@@ -93,9 +93,9 @@ type execResult =
       kind: "error";
       error: string;
     };
-export let formatUsingValidBscNativePath = (
+export let formatCode = (
   code: string,
-  bscNativePath: p.DocumentUri,
+  bscNativePath: p.DocumentUri | null,
   isInterface: boolean
 ): execResult => {
   let extension = isInterface ? c.resiExt : c.resExt;
@@ -104,16 +104,41 @@ export let formatUsingValidBscNativePath = (
     encoding: "utf-8",
   });
   try {
-    let result = childProcess.execFileSync(bscNativePath, [
-      "-color",
-      "never",
-      "-format",
-      formatTempFileFullPath,
-    ]);
-    return {
-      kind: "success",
-      result: result.toString(),
-    };
+    // Default to using the project formatter. If not, use the one we ship with
+    // the analysis binary in the extension itself.
+    if (bscNativePath != null) {
+      let result = childProcess.execFileSync(bscNativePath, [
+        "-color",
+        "never",
+        "-format",
+        formatTempFileFullPath,
+      ]);
+      return {
+        kind: "success",
+        result: result.toString(),
+      };
+    } else {
+      let result = runAnalysisAfterSanityCheck(
+        formatTempFileFullPath,
+        ["format", formatTempFileFullPath],
+        false
+      );
+
+      // The formatter returning an empty string means it couldn't format the
+      // sources, probably because of errors. In that case, we bail from
+      // formatting by returning the unformatted content.
+      if (result === "") {
+        return {
+          kind: "success",
+          result: code,
+        };
+      }
+
+      return {
+        kind: "success",
+        result,
+      };
+    }
   } catch (e) {
     return {
       kind: "error",
@@ -128,7 +153,7 @@ export let formatUsingValidBscNativePath = (
 export let runAnalysisAfterSanityCheck = (
   filePath: p.DocumentUri,
   args: Array<any>,
-  projectRequired=false
+  projectRequired = false
 ) => {
   let binaryPath;
   if (fs.existsSync(c.analysisDevPath)) {
@@ -148,6 +173,7 @@ export let runAnalysisAfterSanityCheck = (
     maxBuffer: Infinity,
   };
   let stdout = childProcess.execFileSync(binaryPath, args, options);
+
   return JSON.parse(stdout.toString());
 };