Collect comments around parentheses in expressions (#13803)

Co-authored-by: Brian Ng <bng412@gmail.com>

packages/babel-generator/test/fixtures/regression/comment-before-parentheses-return-arg-createParenthesizedExpressions/input.js

@@ -0,0 +1,17 @@
+function assertElement(assertFn, shouldBeElement, opt_message) {
+  return /** @type {!Ele	ment} */ (
+	  assertType_(
+	    assertFn,
+		  shouldBeElement,
+		  isElement(shouldBeElement),
+		  'Element expected',
+		  opt_message
+	  )
+	);
+}
+
+const slot = /** @type {!HTMLSlotElement} */ (e.target);
+
+assertElement(
+  /** @type {Element} */ (el),
+);

packages/babel-generator/test/fixtures/regression/comment-before-parentheses-return-arg-createParenthesizedExpressions/options.json

@@ -0,0 +1,4 @@
+{
+  "retainLines": true,
+  "createParenthesizedExpressions": true
+}

packages/babel-generator/test/fixtures/regression/comment-before-parentheses-return-arg-createParenthesizedExpressions/output.js

@@ -0,0 +1,16 @@
+function assertElement(assertFn, shouldBeElement, opt_message) {
+  return (/** @type {!Ele	ment} */
+    assertType_(
+    assertFn,
+    shouldBeElement,
+    isElement(shouldBeElement),
+    'Element expected',
+    opt_message));
+
+
+}
+
+const slot = /** @type {!HTMLSlotElement} */e.target;
+
+assertElement(
+/** @type {Element} */el);

packages/babel-generator/test/fixtures/regression/comment-before-parentheses-return-arg/input.js

@@ -0,0 +1,17 @@
+function assertElement(assertFn, shouldBeElement, opt_message) {
+  return /** @type {!Ele	ment} */ (
+	  assertType_(
+	    assertFn,
+		  shouldBeElement,
+		  isElement(shouldBeElement),
+		  'Element expected',
+		  opt_message
+	  )
+	);
+}
+
+const slot = /** @type {!HTMLSlotElement} */ (e.target);
+
+assertElement(
+  /** @type {Element} */ (el),
+);

packages/babel-generator/test/fixtures/regression/comment-before-parentheses-return-arg/output.js

@@ -0,0 +1,13 @@
+function assertElement(assertFn, shouldBeElement, opt_message) {
+  return (
+    /** @type {!Ele	ment} */
+    assertType_(assertFn, shouldBeElement, isElement(shouldBeElement), 'Element expected', opt_message)
+  );
+}
+
+const slot =
+/** @type {!HTMLSlotElement} */
+e.target;
+assertElement(
+/** @type {Element} */
+el);

packages/babel-parser/src/parser/comments.js

@@ -26,6 +26,7 @@ export type CommentWhitespace = {
   trailingNode: Node | null,
   containingNode: Node | null,
 };
+
 /**
  * Merge comments with node's trailingComments or assign comments to be
  * trailingComments. New comments will be placed before old comments
@@ -42,6 +43,22 @@ function setTrailingComments(node: Node, comments: Array<Comment>) {
   }
 }
 
+/**
+ * Merge comments with node's leadingComments or assign comments to be
+ * leadingComments. New comments will be placed before old comments
+ * because the commentStack is enumerated reversely.
+ *
+ * @param {Node} node
+ * @param {Array<Comment>} comments
+ */
+function setLeadingComments(node: Node, comments: Array<Comment>) {
+  if (node.leadingComments === undefined) {
+    node.leadingComments = comments;
+  } else {
+    node.leadingComments.unshift(...comments);
+  }
+}
+
 /**
  * Merge comments with node's innerComments or assign comments to be
  * innerComments. New comments will be placed before old comments
@@ -50,10 +67,10 @@ function setTrailingComments(node: Node, comments: Array<Comment>) {
  * @param {Node} node
  * @param {Array<Comment>} comments
  */
-export function setInnerComments(node: Node, comments: Array<Comment> | void) {
+export function setInnerComments(node: Node, comments: Array<Comment>) {
   if (node.innerComments === undefined) {
     node.innerComments = comments;
-  } else if (comments !== undefined) {
+  } else {
     node.innerComments.unshift(...comments);
   }
 }
@@ -149,7 +166,7 @@ export default class CommentsParser extends BaseParser {
         setTrailingComments(commentWS.leadingNode, comments);
       }
       if (commentWS.trailingNode !== null) {
-        commentWS.trailingNode.leadingComments = comments;
+        setLeadingComments(commentWS.trailingNode, comments);
       }
     } else {
       /*:: invariant(commentWS.containingNode !== null) */
@@ -238,4 +255,36 @@ export default class CommentsParser extends BaseParser {
       commentWS.leadingNode = null;
     }
   }
+
+  /**
+   * Attach a node to the comment whitespaces right before/after
+   * the given range.
+   *
+   * This is used to properly attach comments around parenthesized
+   * expressions as leading/trailing comments of the inner expression.
+   *
+   * @param {Node} node
+   * @param {number} start
+   * @param {number} end
+   */
+  takeSurroundingComments(node: Node, start: number, end: number) {
+    const { commentStack } = this.state;
+    const commentStackLength = commentStack.length;
+    if (commentStackLength === 0) return;
+    let i = commentStackLength - 1;
+
+    for (; i >= 0; i--) {
+      const commentWS = commentStack[i];
+      const commentEnd = commentWS.end;
+      const commentStart = commentWS.start;
+
+      if (commentStart === end) {
+        commentWS.leadingNode = node;
+      } else if (commentEnd === start) {
+        commentWS.trailingNode = node;
+      } else if (commentEnd < start) {
+        break;
+      }
+    }
+  }
 }

packages/babel-parser/src/parser/expression.js

@@ -1023,9 +1023,13 @@ export default class ExpressionParser extends LValParser {
       call.extra?.trailingComma,
     );
     // mark inner comments of `async()` as inner comments of `async () =>`
+    if (call.innerComments) {
       setInnerComments(node, call.innerComments);
+    }
     // mark trailing comments of `async` to be inner comments
+    if (call.callee.trailingComments) {
       setInnerComments(node, call.callee.trailingComments);
+    }
     return node;
   }
 
@@ -1738,6 +1742,9 @@ export default class ExpressionParser extends LValParser {
     if (!this.options.createParenthesizedExpressions) {
       this.addExtra(val, "parenthesized", true);
       this.addExtra(val, "parenStart", startPos);
+
+      this.takeSurroundingComments(val, startPos, this.state.lastTokEnd);
+
       return val;
     }
 

packages/babel-parser/test/fixtures/comments/basic/nested-parentheses/input.js

@@ -0,0 +1 @@
+1 + /* 0 */(/* 1 */(/* 2 */(/* 3 */i/* 4 */)/* 5 */)/* 6 */)/* 7 */;

packages/babel-parser/test/fixtures/comments/basic/nested-parentheses/output.json

@@ -0,0 +1,128 @@
+{
+  "type": "File",
+  "start":0,"end":68,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":68}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":68,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":68}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start":0,"end":68,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":68}},
+        "expression": {
+          "type": "BinaryExpression",
+          "start":0,"end":60,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":60}},
+          "left": {
+            "type": "NumericLiteral",
+            "start":0,"end":1,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":1}},
+            "extra": {
+              "rawValue": 1,
+              "raw": "1"
+            },
+            "value": 1
+          },
+          "operator": "+",
+          "right": {
+            "type": "Identifier",
+            "start":35,"end":36,"loc":{"start":{"line":1,"column":35},"end":{"line":1,"column":36},"identifierName":"i"},
+            "name": "i",
+            "extra": {
+              "parenthesized": true,
+              "parenStart": 11
+            },
+            "trailingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 4 ",
+                "start":36,"end":43,"loc":{"start":{"line":1,"column":36},"end":{"line":1,"column":43}}
+              },
+              {
+                "type": "CommentBlock",
+                "value": " 5 ",
+                "start":44,"end":51,"loc":{"start":{"line":1,"column":44},"end":{"line":1,"column":51}}
+              },
+              {
+                "type": "CommentBlock",
+                "value": " 6 ",
+                "start":52,"end":59,"loc":{"start":{"line":1,"column":52},"end":{"line":1,"column":59}}
+              }
+            ],
+            "leadingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 0 ",
+                "start":4,"end":11,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":11}}
+              },
+              {
+                "type": "CommentBlock",
+                "value": " 1 ",
+                "start":12,"end":19,"loc":{"start":{"line":1,"column":12},"end":{"line":1,"column":19}}
+              },
+              {
+                "type": "CommentBlock",
+                "value": " 2 ",
+                "start":20,"end":27,"loc":{"start":{"line":1,"column":20},"end":{"line":1,"column":27}}
+              },
+              {
+                "type": "CommentBlock",
+                "value": " 3 ",
+                "start":28,"end":35,"loc":{"start":{"line":1,"column":28},"end":{"line":1,"column":35}}
+              }
+            ]
+          },
+          "trailingComments": [
+            {
+              "type": "CommentBlock",
+              "value": " 7 ",
+              "start":60,"end":67,"loc":{"start":{"line":1,"column":60},"end":{"line":1,"column":67}}
+            }
+          ]
+        }
+      }
+    ],
+    "directives": []
+  },
+  "comments": [
+    {
+      "type": "CommentBlock",
+      "value": " 0 ",
+      "start":4,"end":11,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":11}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 1 ",
+      "start":12,"end":19,"loc":{"start":{"line":1,"column":12},"end":{"line":1,"column":19}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 2 ",
+      "start":20,"end":27,"loc":{"start":{"line":1,"column":20},"end":{"line":1,"column":27}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 3 ",
+      "start":28,"end":35,"loc":{"start":{"line":1,"column":28},"end":{"line":1,"column":35}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 4 ",
+      "start":36,"end":43,"loc":{"start":{"line":1,"column":36},"end":{"line":1,"column":43}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 5 ",
+      "start":44,"end":51,"loc":{"start":{"line":1,"column":44},"end":{"line":1,"column":51}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 6 ",
+      "start":52,"end":59,"loc":{"start":{"line":1,"column":52},"end":{"line":1,"column":59}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 7 ",
+      "start":60,"end":67,"loc":{"start":{"line":1,"column":60},"end":{"line":1,"column":67}}
+    }
+  ]
+}

packages/babel-parser/test/fixtures/comments/basic/sequence-expression/output.json

@@ -24,22 +24,15 @@
             "start":77,"end":84,"loc":{"start":{"line":1,"column":77},"end":{"line":1,"column":84}}
           }
         ],
-        "innerComments": [
+        "expression": {
+          "type": "SequenceExpression",
+          "start":27,"end":47,"loc":{"start":{"line":1,"column":27},"end":{"line":1,"column":47}},
+          "leadingComments": [
             {
               "type": "CommentBlock",
               "value": " 2 ",
               "start":9,"end":16,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":16}}
             },
-          {
-            "type": "CommentBlock",
-            "value": " 8 ",
-            "start":68,"end":75,"loc":{"start":{"line":1,"column":68},"end":{"line":1,"column":75}}
-          }
-        ],
-        "expression": {
-          "type": "SequenceExpression",
-          "start":27,"end":47,"loc":{"start":{"line":1,"column":27},"end":{"line":1,"column":47}},
-          "leadingComments": [
             {
               "type": "CommentBlock",
               "value": " 3 ",
@@ -51,6 +44,11 @@
               "type": "CommentBlock",
               "value": " 7 ",
               "start":58,"end":65,"loc":{"start":{"line":1,"column":58},"end":{"line":1,"column":65}}
+            },
+            {
+              "type": "CommentBlock",
+              "value": " 8 ",
+              "start":68,"end":75,"loc":{"start":{"line":1,"column":68},"end":{"line":1,"column":75}}
             }
           ],
           "extra": {

packages/babel-parser/test/fixtures/comments/regression/13750/input.js

@@ -0,0 +1,5 @@
+if (args[0] === 1  || /* istanbul ignore next */ (args[0] === 2  || args[0] === 3)) {
+  output = args[0] + 10;
+} else {
+  output = 20;
+}

packages/babel-parser/test/fixtures/comments/regression/13750/output.json

@@ -0,0 +1,228 @@
+{
+  "type": "File",
+  "start":0,"end":136,"loc":{"start":{"line":1,"column":0},"end":{"line":5,"column":1}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":136,"loc":{"start":{"line":1,"column":0},"end":{"line":5,"column":1}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "IfStatement",
+        "start":0,"end":136,"loc":{"start":{"line":1,"column":0},"end":{"line":5,"column":1}},
+        "test": {
+          "type": "LogicalExpression",
+          "start":4,"end":82,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":82}},
+          "left": {
+            "type": "BinaryExpression",
+            "start":4,"end":17,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":17}},
+            "left": {
+              "type": "MemberExpression",
+              "start":4,"end":11,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":11}},
+              "object": {
+                "type": "Identifier",
+                "start":4,"end":8,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":8},"identifierName":"args"},
+                "name": "args"
+              },
+              "computed": true,
+              "property": {
+                "type": "NumericLiteral",
+                "start":9,"end":10,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":10}},
+                "extra": {
+                  "rawValue": 0,
+                  "raw": "0"
+                },
+                "value": 0
+              }
+            },
+            "operator": "===",
+            "right": {
+              "type": "NumericLiteral",
+              "start":16,"end":17,"loc":{"start":{"line":1,"column":16},"end":{"line":1,"column":17}},
+              "extra": {
+                "rawValue": 1,
+                "raw": "1"
+              },
+              "value": 1
+            }
+          },
+          "operator": "||",
+          "right": {
+            "type": "LogicalExpression",
+            "start":50,"end":81,"loc":{"start":{"line":1,"column":50},"end":{"line":1,"column":81}},
+            "left": {
+              "type": "BinaryExpression",
+              "start":50,"end":63,"loc":{"start":{"line":1,"column":50},"end":{"line":1,"column":63}},
+              "left": {
+                "type": "MemberExpression",
+                "start":50,"end":57,"loc":{"start":{"line":1,"column":50},"end":{"line":1,"column":57}},
+                "object": {
+                  "type": "Identifier",
+                  "start":50,"end":54,"loc":{"start":{"line":1,"column":50},"end":{"line":1,"column":54},"identifierName":"args"},
+                  "name": "args"
+                },
+                "computed": true,
+                "property": {
+                  "type": "NumericLiteral",
+                  "start":55,"end":56,"loc":{"start":{"line":1,"column":55},"end":{"line":1,"column":56}},
+                  "extra": {
+                    "rawValue": 0,
+                    "raw": "0"
+                  },
+                  "value": 0
+                }
+              },
+              "operator": "===",
+              "right": {
+                "type": "NumericLiteral",
+                "start":62,"end":63,"loc":{"start":{"line":1,"column":62},"end":{"line":1,"column":63}},
+                "extra": {
+                  "rawValue": 2,
+                  "raw": "2"
+                },
+                "value": 2
+              }
+            },
+            "operator": "||",
+            "right": {
+              "type": "BinaryExpression",
+              "start":68,"end":81,"loc":{"start":{"line":1,"column":68},"end":{"line":1,"column":81}},
+              "left": {
+                "type": "MemberExpression",
+                "start":68,"end":75,"loc":{"start":{"line":1,"column":68},"end":{"line":1,"column":75}},
+                "object": {
+                  "type": "Identifier",
+                  "start":68,"end":72,"loc":{"start":{"line":1,"column":68},"end":{"line":1,"column":72},"identifierName":"args"},
+                  "name": "args"
+                },
+                "computed": true,
+                "property": {
+                  "type": "NumericLiteral",
+                  "start":73,"end":74,"loc":{"start":{"line":1,"column":73},"end":{"line":1,"column":74}},
+                  "extra": {
+                    "rawValue": 0,
+                    "raw": "0"
+                  },
+                  "value": 0
+                }
+              },
+              "operator": "===",
+              "right": {
+                "type": "NumericLiteral",
+                "start":80,"end":81,"loc":{"start":{"line":1,"column":80},"end":{"line":1,"column":81}},
+                "extra": {
+                  "rawValue": 3,
+                  "raw": "3"
+                },
+                "value": 3
+              }
+            },
+            "extra": {
+              "parenthesized": true,
+              "parenStart": 49
+            },
+            "leadingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " istanbul ignore next ",
+                "start":22,"end":48,"loc":{"start":{"line":1,"column":22},"end":{"line":1,"column":48}}
+              }
+            ]
+          }
+        },
+        "consequent": {
+          "type": "BlockStatement",
+          "start":84,"end":112,"loc":{"start":{"line":1,"column":84},"end":{"line":3,"column":1}},
+          "body": [
+            {
+              "type": "ExpressionStatement",
+              "start":88,"end":110,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":24}},
+              "expression": {
+                "type": "AssignmentExpression",
+                "start":88,"end":109,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":23}},
+                "operator": "=",
+                "left": {
+                  "type": "Identifier",
+                  "start":88,"end":94,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":8},"identifierName":"output"},
+                  "name": "output"
+                },
+                "right": {
+                  "type": "BinaryExpression",
+                  "start":97,"end":109,"loc":{"start":{"line":2,"column":11},"end":{"line":2,"column":23}},
+                  "left": {
+                    "type": "MemberExpression",
+                    "start":97,"end":104,"loc":{"start":{"line":2,"column":11},"end":{"line":2,"column":18}},
+                    "object": {
+                      "type": "Identifier",
+                      "start":97,"end":101,"loc":{"start":{"line":2,"column":11},"end":{"line":2,"column":15},"identifierName":"args"},
+                      "name": "args"
+                    },
+                    "computed": true,
+                    "property": {
+                      "type": "NumericLiteral",
+                      "start":102,"end":103,"loc":{"start":{"line":2,"column":16},"end":{"line":2,"column":17}},
+                      "extra": {
+                        "rawValue": 0,
+                        "raw": "0"
+                      },
+                      "value": 0
+                    }
+                  },
+                  "operator": "+",
+                  "right": {
+                    "type": "NumericLiteral",
+                    "start":107,"end":109,"loc":{"start":{"line":2,"column":21},"end":{"line":2,"column":23}},
+                    "extra": {
+                      "rawValue": 10,
+                      "raw": "10"
+                    },
+                    "value": 10
+                  }
+                }
+              }
+            }
+          ],
+          "directives": []
+        },
+        "alternate": {
+          "type": "BlockStatement",
+          "start":118,"end":136,"loc":{"start":{"line":3,"column":7},"end":{"line":5,"column":1}},
+          "body": [
+            {
+              "type": "ExpressionStatement",
+              "start":122,"end":134,"loc":{"start":{"line":4,"column":2},"end":{"line":4,"column":14}},
+              "expression": {
+                "type": "AssignmentExpression",
+                "start":122,"end":133,"loc":{"start":{"line":4,"column":2},"end":{"line":4,"column":13}},
+                "operator": "=",
+                "left": {
+                  "type": "Identifier",
+                  "start":122,"end":128,"loc":{"start":{"line":4,"column":2},"end":{"line":4,"column":8},"identifierName":"output"},
+                  "name": "output"
+                },
+                "right": {
+                  "type": "NumericLiteral",
+                  "start":131,"end":133,"loc":{"start":{"line":4,"column":11},"end":{"line":4,"column":13}},
+                  "extra": {
+                    "rawValue": 20,
+                    "raw": "20"
+                  },
+                  "value": 20
+                }
+              }
+            }
+          ],
+          "directives": []
+        }
+      }
+    ],
+    "directives": []
+  },
+  "comments": [
+    {
+      "type": "CommentBlock",
+      "value": " istanbul ignore next ",
+      "start":22,"end":48,"loc":{"start":{"line":1,"column":22},"end":{"line":1,"column":48}}
+    }
+  ]
+}

packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-arrow-function/output.js

@@ -2,6 +2,7 @@ var _ref, _ref2, _ref3;
 
 const result = (_ref3 = -2.2 // -2.2
 , (_ref2 = Math.floor(_ref3) // -3
-, (_ref = () => Math.pow(_ref2, 5), _ref()))); // -243
+, (_ref = () => Math.pow(_ref2, 5) // () => -243
+, _ref()))); // -243
 
 expect(result).toBe(-243);

packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-in-arrow-function/output.js

@@ -3,7 +3,8 @@ const result = () => {
 
   return _ref3 = -2.2 // -2.2
   , (_ref2 = Math.floor(_ref3) // -3
-  , (_ref = () => Math.pow(_ref2, 5), _ref()));
+  , (_ref = () => Math.pow(_ref2, 5) // () => -243
+  , _ref()));
 }; // -243
 
 

packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-arrow-function/output.js

@@ -2,6 +2,7 @@ var _ref, _ref2, _ref3;
 
 const result = (_ref3 = -2.2 // -2.2
 , (_ref2 = Math.floor(_ref3) // -3
-, (_ref = () => Math.pow(_ref2, 5), _ref()))); // -243
+, (_ref = () => Math.pow(_ref2, 5) // () => -243
+, _ref()))); // -243
 
 expect(result).toBe(-243);

packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-in-arrow-function/output.js

@@ -3,7 +3,8 @@ const result = () => {
 
   return _ref3 = -2.2 // -2.2
   , (_ref2 = Math.floor(_ref3) // -3
-  , (_ref = () => Math.pow(_ref2, 5), _ref()));
+  , (_ref = () => Math.pow(_ref2, 5) // () => -243
+  , _ref()));
 }; // -243