Merge pull request #12007 from webpack/bugfix/11990

fix: check statements in path for asi safe

lib/javascript/JavascriptParser.js

@@ -1551,6 +1551,18 @@ class JavascriptParser extends Parser {
 		this.prevStatement = this.statementPath.pop();
 	}
 
+	/**
+	 * Walks a statements that is nested within a parent statement
+	 * and can potentially be a non-block statement.
+	 * This enforces the nested statement to never be in ASI position.
+	 * @param {StatementNode} statement the nested statement
+	 * @returns {void}
+	 */
+	walkNestedStatement(statement) {
+		this.prevStatement = undefined;
+		this.walkStatement(statement);
+	}
+
 	// Real Statements
 	preWalkBlockStatement(statement) {
 		this.preWalkStatements(statement.body);
@@ -1581,15 +1593,15 @@ class JavascriptParser extends Parser {
 		const result = this.hooks.statementIf.call(statement);
 		if (result === undefined) {
 			this.walkExpression(statement.test);
-			this.walkStatement(statement.consequent);
+			this.walkNestedStatement(statement.consequent);
 			if (statement.alternate) {
-				this.walkStatement(statement.alternate);
+				this.walkNestedStatement(statement.alternate);
 			}
 		} else {
 			if (result) {
-				this.walkStatement(statement.consequent);
+				this.walkNestedStatement(statement.consequent);
 			} else if (statement.alternate) {
-				this.walkStatement(statement.alternate);
+				this.walkNestedStatement(statement.alternate);
 			}
 		}
 	}
@@ -1604,7 +1616,7 @@ class JavascriptParser extends Parser {
 			const result = hook.call(statement);
 			if (result === true) return;
 		}
-		this.walkStatement(statement.body);
+		this.walkNestedStatement(statement.body);
 	}
 
 	preWalkWithStatement(statement) {
@@ -1613,7 +1625,7 @@ class JavascriptParser extends Parser {
 
 	walkWithStatement(statement) {
 		this.walkExpression(statement.object);
-		this.walkStatement(statement.body);
+		this.walkNestedStatement(statement.body);
 	}
 
 	preWalkSwitchStatement(statement) {
@@ -1661,7 +1673,7 @@ class JavascriptParser extends Parser {
 
 	walkWhileStatement(statement) {
 		this.walkExpression(statement.test);
-		this.walkStatement(statement.body);
+		this.walkNestedStatement(statement.body);
 	}
 
 	preWalkDoWhileStatement(statement) {
@@ -1669,7 +1681,7 @@ class JavascriptParser extends Parser {
 	}
 
 	walkDoWhileStatement(statement) {
-		this.walkStatement(statement.body);
+		this.walkNestedStatement(statement.body);
 		this.walkExpression(statement.test);
 	}
 
@@ -1687,6 +1699,7 @@ class JavascriptParser extends Parser {
 			if (statement.init) {
 				if (statement.init.type === "VariableDeclaration") {
 					this.blockPreWalkVariableDeclaration(statement.init);
+					this.prevStatement = undefined;
 					this.walkStatement(statement.init);
 				} else {
 					this.walkExpression(statement.init);
@@ -1706,7 +1719,7 @@ class JavascriptParser extends Parser {
 				this.prevStatement = prev;
 				this.walkStatements(body.body);
 			} else {
-				this.walkStatement(body);
+				this.walkNestedStatement(body);
 			}
 		});
 	}
@@ -1735,7 +1748,7 @@ class JavascriptParser extends Parser {
 				this.prevStatement = prev;
 				this.walkStatements(body.body);
 			} else {
-				this.walkStatement(body);
+				this.walkNestedStatement(body);
 			}
 		});
 	}
@@ -1767,7 +1780,7 @@ class JavascriptParser extends Parser {
 				this.prevStatement = prev;
 				this.walkStatements(body.body);
 			} else {
-				this.walkStatement(body);
+				this.walkNestedStatement(body);
 			}
 		});
 	}
@@ -3376,9 +3389,14 @@ class JavascriptParser extends Parser {
 		const currentStatement = this.statementPath[this.statementPath.length - 1];
 		if (currentStatement === undefined) throw new Error("Not in statement");
 		return (
+			// Either asking directly for the end position of the current statement
 			(currentStatement.range[1] === pos && this.semicolons.has(pos)) ||
+			// Or asking for the start position of the current statement,
+			// here we have to check multiple things
 			(currentStatement.range[0] === pos &&
+				// is there a previous statement which might be relevant?
 				this.prevStatement !== undefined &&
+				// is the end position of the previous statement an ASI position?
 				this.semicolons.has(this.prevStatement.range[1]))
 		);
 	}

test/cases/parsing/asi/a.js

@@ -1 +1,11 @@
 export function a() {}
+
+let count = 0;
+
+export function callme() {
+	count++;
+}
+
+export function getCount() {
+	return count;
+}

test/cases/parsing/asi/index.js

@@ -1,4 +1,4 @@
-import {a as b} from "./a";
+import {a as b, callme, getCount} from "./a";
 import * as c from "./b";
 
 function donotcallme() {
@@ -12,4 +12,34 @@ it("should respect asi flag", () => {
 	b();
 	(donotcallme)
 	c;
+
+	var i = 0
+	for (;i < 10;i++) callme()
+	var i = 0
+	for (;i < 10;(function() {
+		i++
+	})()) callme()
+	var i = 0
+	for (;i < 2;i++) {
+		(donotcallme)
+		b();
+	}
+	var i = 0
+	if (i++) callme()
+	var i = 1
+	if (i)
+		(donotcallme)
+	else
+		callme()
+	var i = 0
+	while (i++ < 4) callme()
+	do (donotcallme)
+	while (i++ < 4) callme()
+	var i = 0
+	while (i++ < 4) (function () {
+		var i = 4
+		return callme()
+	})()
+
+	expect(getCount()).toBe(29)
 });

types.d.ts

@@ -4162,6 +4162,13 @@ declare class JavascriptParser extends Parser {
 	preWalkStatement(statement?: any): void;
 	blockPreWalkStatement(statement?: any): void;
 	walkStatement(statement?: any): void;
+
+	/**
+	 * Walks a statements that is nested within a parent statement
+	 * and can potentially be a non-block statement.
+	 * This enforces the nested statement to never be in ASI position.
+	 */
+	walkNestedStatement(statement: Statement): void;
 	preWalkBlockStatement(statement?: any): void;
 	walkBlockStatement(statement?: any): void;
 	walkExpressionStatement(statement?: any): void;