Update: change reporting location for curly rule (refs #12334)

lib/rules/curly.js

@@ -131,15 +131,6 @@ module.exports = {
             return token.value === "else" && token.type === "Keyword";
         }
 
-        /**
-         * Gets the `else` keyword token of a given `IfStatement` node.
-         * @param {ASTNode} node A `IfStatement` node to get.
-         * @returns {Token} The `else` keyword token.
-         */
-        function getElseKeyword(node) {
-            return node.alternate && sourceCode.getFirstTokenBetween(node.consequent, node.alternate, isElseKeywordToken);
-        }
-
         /**
          * Determines whether the given node has an `else` keyword token as the first token after.
          * @param {ASTNode} node The node to check.
@@ -309,6 +300,77 @@ module.exports = {
                 hasUnsafeIf(statement) && isFollowedByElseKeyword(node);
         }
 
+        /**
+         * Missing curly brace reporting location examples:
+         *
+         * The following location should be reported
+         *
+         * if (foo) bar()
+         *          ^^^^^
+         *
+         * while(foo) bar();
+         *            ^^^^^^
+         *
+         * do foo() while(bar)
+         *    ^^^^^
+         *
+         * for(;;) bar();
+         *         ^^^^^^
+         *
+         * for (var foo of bar) console.log(foo)
+         *                      ^^^^^^^^^^^^^^^^
+         *
+         * for (var foo in bar) console.log(foo)
+         *                      ^^^^^^^^^^^^^^^
+         *
+         * if (foo) {bar()} else bar(1);
+         *                       ^^^^^^^
+         *
+         * Unexpected curly brace reporting location examples:
+         *
+         * The following location should be reported
+         *
+         * if (true) foo(); else { baz(); }
+         *                       ^^^^^^^^^^
+         *
+         * for (;;) { foo(); }
+         *          ^^^^^^^^^^
+         *
+         * while (bar) { foo(); }
+         *             ^^^^^^^^^^
+         *
+         * do {foo();} while(bar);
+         *    ^^^^^^^^
+         *
+         * for (var foo of bar) {console.log(foo)}
+         *                      ^^^^^^^^^^^^^^^^^^
+         *
+         * if (foo) bar() else { bar(1) }
+         *                     ^^^^^^^^^^
+         *
+         * Get the location of missing or non missing curly brace.
+         * @param {ASTNode} node the node to check.
+         * @param {string} name name to check.
+         * @returns {Object} Position object.
+         */
+        function getReportingLoc(node, name) {
+            const blockStartLoc = new Set(["do", "for", "for-of", "for-in", "while"]);
+
+            if (name === "else") {
+                return node.alternate.loc;
+            }
+
+            if (blockStartLoc.has(name)) {
+                return node.body.loc;
+            }
+
+            if (name === "if") {
+                return node.consequent.loc;
+            }
+
+            return node.loc;
+        }
+
         /**
          * Prepares to check the body of a node to see if it's a block statement.
          * @param {ASTNode} node The node to report if there's a problem.
@@ -359,19 +421,23 @@ module.exports = {
                 check() {
                     if (this.expected !== null && this.expected !== this.actual) {
                         if (this.expected) {
+                            const loc = getReportingLoc(node, name);
+
                             context.report({
                                 node,
-                                loc: (name !== "else" ? node : getElseKeyword(node)).loc.start,
+                                loc,
                                 messageId: opts && opts.condition ? "missingCurlyAfterCondition" : "missingCurlyAfter",
                                 data: {
                                     name
                                 },
                                 fix: fixer => fixer.replaceText(body, `{${sourceCode.getText(body)}}`)
                             });
                         } else {
+                            const loc = getReportingLoc(node, name);
+
                             context.report({
                                 node,
-                                loc: (name !== "else" ? node : getElseKeyword(node)).loc.start,
+                                loc,
                                 messageId: opts && opts.condition ? "unexpectedCurlyAfterCondition" : "unexpectedCurlyAfter",
                                 data: {
                                     name