TypeScript: remove extra indentation for arrow function on variable declaration with comment (#7094)

* Remove extra indent

* add changelog

* Fix postprocess for range of TypeScript

* Remove locend from postprocess

* Add test for no-smei

* Remove hasLeadingComment

changelog_unreleased/typescript/pr-7094.md

@@ -0,0 +1,26 @@
+#### Remove extra indentation for arrow function on variable declaration with comment([#7094](https://github.com/prettier/prettier/pull/7094) by [@sosukesuzuki](https://github.com/sosukesuzuki))
+
+<!-- prettier-ignore -->
+```ts
+// Input
+const foo = () => {
+  return;
+}
+
+// foo
+;
+
+// Prettier stable
+const foo = () => {
+    return;
+  };
+
+  // foo
+
+// Prettier master
+const foo = () => {
+  return;
+};
+
+// foo
+```

src/language-js/postprocess.js

@@ -1,7 +1,7 @@
 "use strict";
 
 const { getLast } = require("../common/util");
-const { composeLoc } = require("./loc");
+const { composeLoc, locEnd } = require("./loc");
 
 function postprocess(ast, options) {
   visitNode(ast, node => {
@@ -48,7 +48,7 @@ function postprocess(ast, options) {
     if (options.originalText[locEnd(toOverrideNode)] === ";") {
       return;
     }
-    if (options.parser === "flow") {
+    if (Array.isArray(toBeOverriddenNode.range)) {
       toBeOverriddenNode.range = [
         toBeOverriddenNode.range[0],
         toOverrideNode.range[1]
@@ -60,10 +60,6 @@ function postprocess(ast, options) {
       end: toBeOverriddenNode.loc.end
     });
   }
-
-  function locEnd(node) {
-    return options.parser === "flow" ? node.range[1] : node.end;
-  }
 }
 
 function visitNode(node, fn, parent, property) {

tests/typescript_arrow/__snapshots__/jsfmt.spec.js.snap

@@ -40,3 +40,108 @@ app.get("/", (req, res): void => {
 
 ================================================================================
 `;
+
+exports[`arrow_regression.js 2`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+const bar = (...varargs:any[]) => {
+  console.log(varargs);
+};
+
+const foo = (x:string):void => (
+  bar(
+    x,
+    () => {},
+    () => {}
+  )
+);
+
+app.get("/", (req, res): void => {
+  res.send("Hello world");
+});
+
+=====================================output=====================================
+const bar = (...varargs: any[]) => {
+  console.log(varargs)
+}
+
+const foo = (x: string): void =>
+  bar(
+    x,
+    () => {},
+    () => {}
+  )
+
+app.get("/", (req, res): void => {
+  res.send("Hello world")
+})
+
+================================================================================
+`;
+
+exports[`comments.js 1`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+const fn1 = () => {
+  return;
+} /* foo */;
+
+const fn2 = () => {
+  return;
+}
+
+// foo
+;
+
+=====================================output=====================================
+const fn1 = () => {
+  return;
+}; /* foo */
+
+const fn2 = () => {
+  return;
+};
+
+// foo
+
+================================================================================
+`;
+
+exports[`comments.js 2`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+const fn1 = () => {
+  return;
+} /* foo */;
+
+const fn2 = () => {
+  return;
+}
+
+// foo
+;
+
+=====================================output=====================================
+const fn1 = () => {
+  return
+} /* foo */
+
+const fn2 = () => {
+  return
+}
+
+// foo
+
+================================================================================
+`;

tests/typescript_arrow/comments.js

@@ -0,0 +1,10 @@
+const fn1 = () => {
+  return;
+} /* foo */;
+
+const fn2 = () => {
+  return;
+}
+
+// foo
+;

tests/typescript_arrow/jsfmt.spec.js

@@ -1 +1,2 @@
 run_spec(__dirname, ["typescript"]);
+run_spec(__dirname, ["typescript"], { semi: false });