Bug 1317397: Only set lastIndex for global or sticky RegExps in RegExpBuiltinExec per ES2017

1 files changed, 118 insertions, 0 deletions

diff --git a/js/src/tests/ecma_2017/lastIndex-search.js b/js/src/tests/ecma_2017/lastIndex-search.js
new file mode 100644
index 000000000..5953b3a88
--- /dev/null
+++ b/js/src/tests/ecma_2017/lastIndex-search.js
@@ -0,0 +1,118 @@
+// RegExp.prototype[Symbol.search]: Test lastIndex changes for ES2017.
+
+// RegExp-like class to test the RegExp method slow paths.
+class DuckRegExp extends RegExp {
+    constructor(pattern, flags) {
+        return Object.create(DuckRegExp.prototype, {
+            regExp: {
+                value: new RegExp(pattern, flags)
+            },
+            lastIndex: {
+                value: 0, writable: true, enumerable: false, configurable: false
+            }
+        });
+    }
+
+    exec(...args) {
+        this.regExp.lastIndex = this.lastIndex;
+        try {
+            return this.regExp.exec(...args);
+        } finally {
+            if (this.global || this.sticky)
+                this.lastIndex = this.regExp.lastIndex;
+        }
+    }
+
+    get source() { return this.regExp.source; }
+
+    get global() { return this.regExp.global; }
+    get ignoreCase() { return this.regExp.ignoreCase; }
+    get multiline() { return this.regExp.multiline; }
+    get sticky() { return this.regExp.sticky; }
+    get unicode() { return this.regExp.unicode; }
+}
+
+// Test various combinations of:
+// - Pattern matches or doesn't match
+// - Global and/or sticky flag is set.
+// - lastIndex exceeds the input string length
+// - lastIndex is +-0
+const testCasesNotPositiveZero = [
+    { regExp: /a/,  lastIndex: -1, input: "a" },
+    { regExp: /a/g, lastIndex: -1, input: "a" },
+    { regExp: /a/y, lastIndex: -1, input: "a" },
+
+    { regExp: /a/,  lastIndex: 100, input: "a" },
+    { regExp: /a/g, lastIndex: 100, input: "a" },
+    { regExp: /a/y, lastIndex: 100, input: "a" },
+
+    { regExp: /a/,  lastIndex: -1, input: "b" },
+    { regExp: /a/g, lastIndex: -1, input: "b" },
+    { regExp: /a/y, lastIndex: -1, input: "b" },
+
+    { regExp: /a/,  lastIndex: -0, input: "a" },
+    { regExp: /a/g, lastIndex: -0, input: "a" },
+    { regExp: /a/y, lastIndex: -0, input: "a" },
+
+    { regExp: /a/,  lastIndex: -0, input: "b" },
+    { regExp: /a/g, lastIndex: -0, input: "b" },
+    { regExp: /a/y, lastIndex: -0, input: "b" },
+];
+
+const testCasesPositiveZero = [
+    { regExp: /a/,  lastIndex: 0, input: "a" },
+    { regExp: /a/g, lastIndex: 0, input: "a" },
+    { regExp: /a/y, lastIndex: 0, input: "a" },
+
+    { regExp: /a/,  lastIndex: 0, input: "b" },
+    { regExp: /a/g, lastIndex: 0, input: "b" },
+    { regExp: /a/y, lastIndex: 0, input: "b" },
+];
+
+const testCases = [...testCasesNotPositiveZero, ...testCasesPositiveZero];
+
+for (let Constructor of [RegExp, DuckRegExp]) {
+    // Basic test.
+    for (let {regExp, lastIndex, input} of testCases) {
+        let re = new Constructor(regExp);
+        re.lastIndex = lastIndex;
+        re[Symbol.search](input);
+        assertEq(re.lastIndex, lastIndex);
+    }
+
+    // Test when lastIndex is non-writable and not positive zero.
+    for (let {regExp, lastIndex, input} of testCasesNotPositiveZero) {
+        let re = new Constructor(regExp);
+        Object.defineProperty(re, "lastIndex", { value: lastIndex, writable: false });
+        assertThrowsInstanceOf(() => re[Symbol.search](input), TypeError);
+        assertEq(re.lastIndex, lastIndex);
+    }
+
+    // Test when lastIndex is non-writable and positive zero.
+    for (let {regExp, lastIndex, input} of testCasesPositiveZero) {
+        let re = new Constructor(regExp);
+        Object.defineProperty(re, "lastIndex", { value: lastIndex, writable: false });
+        if (re.global || re.sticky) {
+            assertThrowsInstanceOf(() => re[Symbol.search](input), TypeError);
+        } else {
+            re[Symbol.search](input);
+        }
+        assertEq(re.lastIndex, lastIndex);
+    }
+
+    // Test lastIndex isn't converted to a number.
+    for (let {regExp, lastIndex, input} of testCases) {
+        let re = new RegExp(regExp);
+        let badIndex = {
+            valueOf() {
+                assertEq(false, true);
+            }
+        };
+        re.lastIndex = badIndex;
+        re[Symbol.search](input);
+        assertEq(re.lastIndex, badIndex);
+    }
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);