[es6] early error when Identifier is an escaped reserved word

test/cctest/test-parsing.cc

Index: test/cctest/test-parsing.cc
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index ec5d5f9d9badc157b88a26b9e543642ccd5b0712..d1e000ef5278745d2eaa631c619750974c304d5d 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -7235,3 +7235,118 @@ TEST(LetSloppyOnly) {
   RunParserSyncTest(context_data, fail_data, kError, NULL, 0, fail_flags,
                     arraysize(fail_flags));
 }
+
+
+TEST(EscapedKeywords) {

[adamk, 2015/11/03 23:00:57]

I think you also want some more non-error cases: yield outside of a generator,
arguments and eval in sloppy mode, along with other things in that old
"implements", "interface", etc list.

[caitp (gmail), 2015/11/04 04:49:25]

I've added sloppy vs strict tests for the future reserved words cases, as well
as non-generator yield

+  // clang-format off
+  const char* sloppy_context_data[][2] = {
+    {"", ""},
+    {NULL, NULL}
+  };
+
+  const char* strict_context_data[][2] = {
+    {"'use strict';", ""},
+    {NULL, NULL}
+  };
+
+  const char* fail_data[] = {
+    "for (var i = 0; i < 100; ++i) { br\\u0065ak; }",

[caitp (gmail), 2015/11/03 17:19:13]

There are probably some good test cases missing, like alternative declaration
forms (`catch (th\u0079s) { ... }`), I'm not sure what else.

+    "cl\\u0061ss Foo {}",
+    "var x = cl\\u0061ss {}",
+    "\\u0063onst foo = 1;",
+    "while (i < 10) { if (i++ & 1) c\\u006fntinue; this.x++; }",
+    "d\\u0065bugger;",
+    "d\\u0065lete this.a;",
+    "\\u0063o { } while(0)",
+    "if (d\\u006f { true }) {}",
+    "if (false) { this.a = 1; } \\u0065lse { this.b = 1; }",
+    "e\\u0078port var foo;",

[adamk, 2015/11/03 23:00:57]

This would already be failing since you're not parsing a module, so I don't
think this makes sense in this list. You could make a separate test case for
modules if you'd like (but I'm also fine with leaving that for another time).

[caitp (gmail), 2015/11/04 04:49:25]

I've added a helper for testing module parsing, and am using that a bit, it
might be useful for other tests in the future. It looked like less of a pain to
do it that way than the way other module tests are written

+    "try { } catch (e) {} f\\u0069nally { }",
+    "f\\u006fr (var i = 0; i < 10; ++i);",
+    "f\\u0075nction fn() {}",
+    "var f = f\\u0075nction() {}",
+    "\\u0069f (true) { }",
+    "\\u0069mport blah from './foo.js';",

[adamk, 2015/11/03 23:00:57]

same here as above for export

[caitp (gmail), 2015/11/04 04:49:25]

These would have been errors before, but only because of the `blah` following a
previous `Identifier`. Now, the error is found before the second token is
reached, so I think it's sort of good to keep it.

But yeah, I'll add a second set of tests with the module flag enabled

+    "n\\u0065w function f() {}",
+    "(function() { r\\u0065turn; })()",
+    "class C extends function() {} { constructor() { sup\\u0065r() } }",
+    "class C extends function() {} { constructor() { sup\\u0065r.a = 1 } }",
+    "sw\\u0069tch (this.a) {}",
+    "var x = th\\u0069s;",
+    "th\\u0069s.a = 1;",
+    "thr\\u006fw 'boo';",
+    "t\\u0072y { true } catch (e) {}",
+    "var x = typ\\u0065of 'blah'",
+    "v\\u0061r a = true",
+    "var v\\u0061r = true",
+    "(function() { return v\\u006fid 0; })()",
+    "wh\\u0069le (true) { }",
+    "w\\u0069th (this.scope) { }",
+    "(function*() { y\\u0069eld 1; })()",
+
+    "var \\u0065num = 1;",
+    "var { \\u0065num } = {}",
+    "(\\u0065num = 1);",
+
+    // Null / Boolean literals
+    "(x === n\\u0075ll);",
+    "var x = n\\u0075ll;",
+    "var n\\u0075ll = 1;",
+    "var { n\\u0075ll } = { 1 };",
+    "n\\u0075ll = 1;",
+    "(x === tr\\u0075e);",
+    "var x = tr\\u0075e;",
+    "var tr\\u0075e = 1;",
+    "var { tr\\u0075e } = {};",
+    "tr\\u0075e = 1;",
+    "(x === f\\u0061lse);",
+    "var x = f\\u0061lse;",
+    "var f\\u0061lse = 1;",
+    "var { f\\u0061lse } = {};",
+    "f\\u0061lse = 1;",
+
+    // TODO(caitp): consistent error messages for labeled statements and
+    // expressions
+    "switch (this.a) { c\\u0061se 6: break; }",
+    "try { } c\\u0061tch (e) {}",
+    "switch (this.a) { d\\u0065fault: break; }",
+    "class C \\u0065xtends function B() {} {}",
+    "for (var a i\\u006e this) {}",
+    "if ('foo' \\u0069n this) {}",
+    "if (this \\u0069nstanceof Array) {}",
+    "(n\\u0065w function f() {})",
+    "(typ\\u0065of 123)",
+    "(v\\u006fid 0)",
+    "do { ; } wh\\u0069le (true) { }",
+    "(function*() { return (n++, y\\u0069eld 1); })()",
+    "class C { st\\u0061tic bar() {} }",
+    NULL
+  };
+  // clang-format on
+
+  static const ParserFlag always_flags[] = {
+      kAllowHarmonySloppy, kAllowHarmonyDestructuring};
+  RunParserSyncTest(sloppy_context_data, fail_data, kError, NULL, 0,
+                    always_flags, arraysize(always_flags));
+  RunParserSyncTest(strict_context_data, fail_data, kError, NULL, 0,
+                    always_flags, arraysize(always_flags));
+
+  // clang-format off
+  const char* let_data[] = {
+    "var l\\u0065t = 1;",
+    "l\\u0065t = 1;",
+    "(l\\u0065t === 1);",
+    NULL
+  };
+  // clang-format on
+
+  RunParserSyncTest(sloppy_context_data, let_data, kSuccess, NULL, 0,
+                    always_flags, arraysize(always_flags));
+  RunParserSyncTest(strict_context_data, let_data, kError, NULL, 0,
+                    always_flags, arraysize(always_flags));
+
+  static const ParserFlag sloppy_let_flags[] = {
+      kAllowHarmonySloppy, kAllowHarmonySloppyLet, kAllowHarmonyDestructuring};
+  RunParserSyncTest(sloppy_context_data, let_data, kError, NULL, 0,
+                    sloppy_let_flags, arraysize(sloppy_let_flags));
+}