Fix inconsistent printing of class method comment (#18147)

changelog_unreleased/javascript/18147.md

@@ -0,0 +1,48 @@
+#### Fix inconsistent comment print between class methods and object methods (#18147 by @fisker)
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+class x {
+  method() // Class method
+  {
+    return 1
+  }
+}
+
+const object = {
+  method() // Object method
+  {
+    return 1
+  }
+}
+
+// Prettier stable
+class x {
+  method() { // Class method
+    return 1;
+  }
+}
+
+const object = {
+  method() {
+    // Object method
+    return 1;
+  },
+};
+
+// Prettier main
+class x {
+  method() {
+    // class method
+    return 1;
+  }
+}
+
+const object = {
+  method() {
+    // object method
+    return 1;
+  },
+};
+```

src/language-js/comments/handle-comments.js

@@ -694,19 +694,21 @@ function handleLastFunctionArgComments({
   // Comment between function parameters parentheses and function body
   if (
     !isBlockComment(comment) &&
-    (enclosingNode?.type === "FunctionDeclaration" ||
-      enclosingNode?.type === "FunctionExpression" ||
-      enclosingNode?.type === "ObjectMethod") &&
     followingNode?.type === "BlockStatement" &&
-    enclosingNode.body === followingNode
+    isFunctionLikeNode(enclosingNode)
   ) {
-    const characterAfterCommentIndex = getNextNonSpaceNonCommentCharacterIndex(
-      text,
-      locEnd(comment),
-    );
-    if (characterAfterCommentIndex === locStart(followingNode)) {
-      addBlockStatementFirstComment(followingNode, comment);
-      return true;
+    const functionBody =
+      enclosingNode.type === "MethodDefinition"
+        ? enclosingNode.value.body
+        : enclosingNode.body;
+
+    if (functionBody === followingNode) {
+      const characterAfterCommentIndex =
+        getNextNonSpaceNonCommentCharacterIndex(text, locEnd(comment));
+      if (characterAfterCommentIndex === locStart(followingNode)) {
+        addBlockStatementFirstComment(followingNode, comment);
+        return true;
+      }
     }
   }
 

tests/config/run-format-test.js

@@ -22,7 +22,6 @@ const RANGE_END_PLACEHOLDER = "<<<PRETTIER_RANGE_END>>>";
 // TODO: these test files need fix
 const unstableTests = new Map(
   [
-    "js/class-comment/misc.js",
     ["js/comments/dangling_array.js", (options) => options.semi === false],
     ["js/comments/jsx.js", (options) => options.semi === false],
     "js/comments/return-statement.js",

tests/format/js/class-comment/__snapshots__/format.test.js.snap

@@ -41,7 +41,8 @@ class x {
 
 =====================================output=====================================
 class x {
-  focus() { // comment 1
+  focus() {
+    // comment 1
     // comment 2
   }
 }

tests/format/js/comments/function/18146.js

@@ -0,0 +1,70 @@
+class x {
+  a() // class 1
+  {
+  }
+
+  b() // class 2
+  {
+    // comment
+  }
+
+  c() // class 3
+  {
+    call()
+  }
+
+  constructor() // class constructor
+  {}
+
+  static staticMethod() // class static
+  {}
+
+  get getter() // class getter
+  {}
+}
+
+const x2 = {
+  a() // object 1
+  {
+  },
+
+  b() // object 2
+  {
+    // comment
+  },
+
+  c() // object 3
+  {
+    call()
+  }
+}
+
+function a() // function declaration 1
+{
+    // comment
+}
+
+function b() // function declaration 1
+{
+}
+
+function c() // function declaration 1
+{
+    call()
+}
+
+a = [
+  function a() // function expression 1
+  {
+      // comment
+  },
+
+  function b() // function expression 1
+  {
+  },
+
+  function c() // function expression 1
+  {
+      call()
+  },
+]

tests/format/js/comments/function/__snapshots__/format.test.js.snap

@@ -1,5 +1,160 @@
 // Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
 
+exports[`18146.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+class x {
+  a() // class 1
+  {
+  }
+
+  b() // class 2
+  {
+    // comment
+  }
+
+  c() // class 3
+  {
+    call()
+  }
+
+  constructor() // class constructor
+  {}
+
+  static staticMethod() // class static
+  {}
+
+  get getter() // class getter
+  {}
+}
+
+const x2 = {
+  a() // object 1
+  {
+  },
+
+  b() // object 2
+  {
+    // comment
+  },
+
+  c() // object 3
+  {
+    call()
+  }
+}
+
+function a() // function declaration 1
+{
+    // comment
+}
+
+function b() // function declaration 1
+{
+}
+
+function c() // function declaration 1
+{
+    call()
+}
+
+a = [
+  function a() // function expression 1
+  {
+      // comment
+  },
+
+  function b() // function expression 1
+  {
+  },
+
+  function c() // function expression 1
+  {
+      call()
+  },
+]
+
+=====================================output=====================================
+class x {
+  a() {
+    // class 1
+  }
+
+  b() {
+    // class 2
+    // comment
+  }
+
+  c() {
+    // class 3
+    call();
+  }
+
+  constructor() {
+    // class constructor
+  }
+
+  static staticMethod() {
+    // class static
+  }
+
+  get getter() {
+    // class getter
+  }
+}
+
+const x2 = {
+  a() {
+    // object 1
+  },
+
+  b() {
+    // object 2
+    // comment
+  },
+
+  c() {
+    // object 3
+    call();
+  },
+};
+
+function a() {
+  // function declaration 1
+  // comment
+}
+
+function b() {
+  // function declaration 1
+}
+
+function c() {
+  // function declaration 1
+  call();
+}
+
+a = [
+  function a() {
+    // function expression 1
+    // comment
+  },
+
+  function b() {
+    // function expression 1
+  },
+
+  function c() {
+    // function expression 1
+    call();
+  },
+];
+
+================================================================================
+`;
+
 exports[`between-parentheses-and-function-body.js format 1`] = `
 ====================================options=====================================
 parsers: ["babel", "flow", "typescript"]
@@ -42,6 +197,17 @@ a = {
   {},
 }
 
+class A {
+
+  foo()
+  // this is a function
+  {}
+
+  bar = function()
+  // this is a function
+  {}
+}
+
 =====================================output=====================================
 function function_declaration() {
   // this is a function
@@ -74,5 +240,15 @@ a = {
   },
 };
 
+class A {
+  foo() {
+    // this is a function
+  }
+
+  bar = function () {
+    // this is a function
+  };
+}
+
 ================================================================================
 `;

tests/format/js/comments/function/between-parentheses-and-function-body.js

@@ -33,3 +33,14 @@ a = {
   // this is a function
   {},
 }
+
+class A {
+
+  foo()
+  // this is a function
+  {}
+
+  bar = function()
+  // this is a function
+  {}
+}