fix(ast): checks validity of an identifier (#360)

added test cases for validate identifier

lib/utils/ast-utils.js

@@ -1,4 +1,5 @@
 const hashtable = require("./hashtable");
+const validateIdentifier = require("./validate-identifier");
 
 function safeTraverse(obj, paths) {
 	let val = obj;
@@ -149,8 +150,8 @@ function createIdentifierOrLiteral(j, val) {
 			return createExternalRegExp(j, val);
 		} else {
 			// Use identifier instead
-			// TODO: Check if literalVal is a valid Identifier!
-			return j.identifier(literalVal);
+			if (!validateIdentifier.isKeyword(literalVal) || !validateIdentifier.isIdentifierStart(literalVal) || !validateIdentifier.isIdentifierChar(literalVal))
+				return j.identifier(literalVal);
 		}
 	}
 	return j.literal(literalVal);

lib/utils/validate-identifier.js

@@ -0,0 +1,128 @@
+// This is a trick taken from Esprima. It turns out that, on
+// non-Chrome browsers, to check whether a string is in a set, a
+// predicate containing a big ugly `switch` statement is faster than
+// a regular expression, and on Chrome the two are about on par.
+// https://tc39.github.io/ecma262/#sec-keywords
+function isKeyword(code) {
+	switch (code.length) {
+		case 2:
+			return (code === "if") || (code === "in") || (code === "do");
+		case 3:
+			return (code === "var") || (code === "for") || (code === "new") ||
+				(code === "try") || (code === "let");
+		case 4:
+			return (code === "this") || (code === "case") ||
+				(code === "void") || (code === "with") || (code === "enum") || (code === "true") ||
+				(code === "null") || (code === "eval");
+		case 5:
+			return (code === "while") || (code === "break") || (code === "catch") ||
+				(code === "throw") || (code === "const") || (code === "yield") ||
+				(code === "class") || (code === "super") || (code === "false") || (code === "await");
+		case 6:
+			return (code === "return") || (code === "typeof") || (code === "delete") ||
+				(code === "switch") || (code === "export") || (code === "import") ||
+				(code === "static") || (code === "public") ;
+		case 7:
+			return (code === "default") || (code === "finally") || (code === "extends") ||
+				(code === "private") || (code === "package");
+		case 8:
+			return (code === "function") || (code === "continue") || (code === "debugger");
+		case 9:
+			return (code === "protected") || (code === "interface") || (code === "arguments");
+		case 10:
+			return (code === "instanceof") || (code === "implements");
+		default:
+			return false;
+	}
+}
+// ## Character categories
+
+// Big ugly regular expressions that match characters in the
+// whitespace, identifier, and identifier-start categories. These
+// are only applied when a character is found to actually have a
+// code point above 128.
+
+let nonASCIIidentifierStartChars = "\xaa\xb5\xba\xc0-\xd6\xd8-\xf6\xf8-\u02c1\u02c6-\u02d1\u02e0-\u02e4\u02ec\u02ee\u0370-\u0374\u0376\u0377\u037a-\u037d\u037f\u0386\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03f5\u03f7-\u0481\u048a-\u052f\u0531-\u0556\u0559\u0561-\u0587\u05d0-\u05ea\u05f0-\u05f2\u0620-\u064a\u066e\u066f\u0671-\u06d3\u06d5\u06e5\u06e6\u06ee\u06ef\u06fa-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07ca-\u07ea\u07f4\u07f5\u07fa\u0800-\u0815\u081a\u0824\u0828\u0840-\u0858\u08a0-\u08b2\u0904-\u0939\u093d\u0950\u0958-\u0961\u0971-\u0980\u0985-\u098c\u098f\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2\u09b6-\u09b9\u09bd\u09ce\u09dc\u09dd\u09df-\u09e1\u09f0\u09f1\u0a05-\u0a0a\u0a0f\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32\u0a33\u0a35\u0a36\u0a38\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8d\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2\u0ab3\u0ab5-\u0ab9\u0abd\u0ad0\u0ae0\u0ae1\u0b05-\u0b0c\u0b0f\u0b10\u0b13-\u0b28\u0b2a-\u0b30\u0b32\u0b33\u0b35-\u0b39\u0b3d\u0b5c\u0b5d\u0b5f-\u0b61\u0b71\u0b83\u0b85-\u0b8a\u0b8e-\u0b90\u0b92-\u0b95\u0b99\u0b9a\u0b9c\u0b9e\u0b9f\u0ba3\u0ba4\u0ba8-\u0baa\u0bae-\u0bb9\u0bd0\u0c05-\u0c0c\u0c0e-\u0c10\u0c12-\u0c28\u0c2a-\u0c39\u0c3d\u0c58\u0c59\u0c60\u0c61\u0c85-\u0c8c\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cbd\u0cde\u0ce0\u0ce1\u0cf1\u0cf2\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d3a\u0d3d\u0d4e\u0d60\u0d61\u0d7a-\u0d7f\u0d85-\u0d96\u0d9a-\u0db1\u0db3-\u0dbb\u0dbd\u0dc0-\u0dc6\u0e01-\u0e30\u0e32\u0e33\u0e40-\u0e46\u0e81\u0e82\u0e84\u0e87\u0e88\u0e8a\u0e8d\u0e94-\u0e97\u0e99-\u0e9f\u0ea1-\u0ea3\u0ea5\u0ea7\u0eaa\u0eab\u0ead-\u0eb0\u0eb2\u0eb3\u0ebd\u0ec0-\u0ec4\u0ec6\u0edc-\u0edf\u0f00\u0f40-\u0f47\u0f49-\u0f6c\u0f88-\u0f8c\u1000-\u102a\u103f\u1050-\u1055\u105a-\u105d\u1061\u1065\u1066\u106e-\u1070\u1075-\u1081\u108e\u10a0-\u10c5\u10c7\u10cd\u10d0-\u10fa\u10fc-\u1248\u124a-\u124d\u1250-\u1256\u1258\u125a-\u125d\u1260-\u1288\u128a-\u128d\u1290-\u12b0\u12b2-\u12b5\u12b8-\u12be\u12c0\u12c2-\u12c5\u12c8-\u12d6\u12d8-\u1310\u1312-\u1315\u1318-\u135a\u1380-\u138f\u13a0-\u13f4\u1401-\u166c\u166f-\u167f\u1681-\u169a\u16a0-\u16ea\u16ee-\u16f8\u1700-\u170c\u170e-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176c\u176e-\u1770\u1780-\u17b3\u17d7\u17dc\u1820-\u1877\u1880-\u18a8\u18aa\u18b0-\u18f5\u1900-\u191e\u1950-\u196d\u1970-\u1974\u1980-\u19ab\u19c1-\u19c7\u1a00-\u1a16\u1a20-\u1a54\u1aa7\u1b05-\u1b33\u1b45-\u1b4b\u1b83-\u1ba0\u1bae\u1baf\u1bba-\u1be5\u1c00-\u1c23\u1c4d-\u1c4f\u1c5a-\u1c7d\u1ce9-\u1cec\u1cee-\u1cf1\u1cf5\u1cf6\u1d00-\u1dbf\u1e00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec\u1ff2-\u1ff4\u1ff6-\u1ffc\u2071\u207f\u2090-\u209c\u2102\u2107\u210a-\u2113\u2115\u2118-\u211d\u2124\u2126\u2128\u212a-\u2139\u213c-\u213f\u2145-\u2149\u214e\u2160-\u2188\u2c00-\u2c2e\u2c30-\u2c5e\u2c60-\u2ce4\u2ceb-\u2cee\u2cf2\u2cf3\u2d00-\u2d25\u2d27\u2d2d\u2d30-\u2d67\u2d6f\u2d80-\u2d96\u2da0-\u2da6\u2da8-\u2dae\u2db0-\u2db6\u2db8-\u2dbe\u2dc0-\u2dc6\u2dc8-\u2dce\u2dd0-\u2dd6\u2dd8-\u2dde\u3005-\u3007\u3021-\u3029\u3031-\u3035\u3038-\u303c\u3041-\u3096\u309b-\u309f\u30a1-\u30fa\u30fc-\u30ff\u3105-\u312d\u3131-\u318e\u31a0-\u31ba\u31f0-\u31ff\u3400-\u4db5\u4e00-\u9fcc\ua000-\ua48c\ua4d0-\ua4fd\ua500-\ua60c\ua610-\ua61f\ua62a\ua62b\ua640-\ua66e\ua67f-\ua69d\ua6a0-\ua6ef\ua717-\ua71f\ua722-\ua788\ua78b-\ua78e\ua790-\ua7ad\ua7b0\ua7b1\ua7f7-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8f2-\ua8f7\ua8fb\ua90a-\ua925\ua930-\ua946\ua960-\ua97c\ua984-\ua9b2\ua9cf\ua9e0-\ua9e4\ua9e6-\ua9ef\ua9fa-\ua9fe\uaa00-\uaa28\uaa40-\uaa42\uaa44-\uaa4b\uaa60-\uaa76\uaa7a\uaa7e-\uaaaf\uaab1\uaab5\uaab6\uaab9-\uaabd\uaac0\uaac2\uaadb-\uaadd\uaae0-\uaaea\uaaf2-\uaaf4\uab01-\uab06\uab09-\uab0e\uab11-\uab16\uab20-\uab26\uab28-\uab2e\uab30-\uab5a\uab5c-\uab5f\uab64\uab65\uabc0-\uabe2\uac00-\ud7a3\ud7b0-\ud7c6\ud7cb-\ud7fb\uf900-\ufa6d\ufa70-\ufad9\ufb00-\ufb06\ufb13-\ufb17\ufb1d\ufb1f-\ufb28\ufb2a-\ufb36\ufb38-\ufb3c\ufb3e\ufb40\ufb41\ufb43\ufb44\ufb46-\ufbb1\ufbd3-\ufd3d\ufd50-\ufd8f\ufd92-\ufdc7\ufdf0-\ufdfb\ufe70-\ufe74\ufe76-\ufefc\uff21-\uff3a\uff41-\uff5a\uff66-\uffbe\uffc2-\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc";
+let nonASCIIidentifierChars = "\u200c\u200d\xb7\u0300-\u036f\u0387\u0483-\u0487\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u0669\u0670\u06d6-\u06dc\u06df-\u06e4\u06e7\u06e8\u06ea-\u06ed\u06f0-\u06f9\u0711\u0730-\u074a\u07a6-\u07b0\u07c0-\u07c9\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0859-\u085b\u08e4-\u0903\u093a-\u093c\u093e-\u094f\u0951-\u0957\u0962\u0963\u0966-\u096f\u0981-\u0983\u09bc\u09be-\u09c4\u09c7\u09c8\u09cb-\u09cd\u09d7\u09e2\u09e3\u09e6-\u09ef\u0a01-\u0a03\u0a3c\u0a3e-\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a66-\u0a71\u0a75\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0ae2\u0ae3\u0ae6-\u0aef\u0b01-\u0b03\u0b3c\u0b3e-\u0b44\u0b47\u0b48\u0b4b-\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b66-\u0b6f\u0b82\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0be6-\u0bef\u0c00-\u0c03\u0c3e-\u0c44\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0c66-\u0c6f\u0c81-\u0c83\u0cbc\u0cbe-\u0cc4\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0ce6-\u0cef\u0d01-\u0d03\u0d3e-\u0d44\u0d46-\u0d48\u0d4a-\u0d4d\u0d57\u0d62\u0d63\u0d66-\u0d6f\u0d82\u0d83\u0dca\u0dcf-\u0dd4\u0dd6\u0dd8-\u0ddf\u0de6-\u0def\u0df2\u0df3\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0e50-\u0e59\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0ed0-\u0ed9\u0f18\u0f19\u0f20-\u0f29\u0f35\u0f37\u0f39\u0f3e\u0f3f\u0f71-\u0f84\u0f86\u0f87\u0f8d-\u0f97\u0f99-\u0fbc\u0fc6\u102b-\u103e\u1040-\u1049\u1056-\u1059\u105e-\u1060\u1062-\u1064\u1067-\u106d\u1071-\u1074\u1082-\u108d\u108f-\u109d\u135d-\u135f\u1369-\u1371\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b4-\u17d3\u17dd\u17e0-\u17e9\u180b-\u180d\u1810-\u1819\u18a9\u1920-\u192b\u1930-\u193b\u1946-\u194f\u19b0-\u19c0\u19c8\u19c9\u19d0-\u19da\u1a17-\u1a1b\u1a55-\u1a5e\u1a60-\u1a7c\u1a7f-\u1a89\u1a90-\u1a99\u1ab0-\u1abd\u1b00-\u1b04\u1b34-\u1b44\u1b50-\u1b59\u1b6b-\u1b73\u1b80-\u1b82\u1ba1-\u1bad\u1bb0-\u1bb9\u1be6-\u1bf3\u1c24-\u1c37\u1c40-\u1c49\u1c50-\u1c59\u1cd0-\u1cd2\u1cd4-\u1ce8\u1ced\u1cf2-\u1cf4\u1cf8\u1cf9\u1dc0-\u1df5\u1dfc-\u1dff\u203f\u2040\u2054\u20d0-\u20dc\u20e1\u20e5-\u20f0\u2cef-\u2cf1\u2d7f\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua620-\ua629\ua66f\ua674-\ua67d\ua69f\ua6f0\ua6f1\ua802\ua806\ua80b\ua823-\ua827\ua880\ua881\ua8b4-\ua8c4\ua8d0-\ua8d9\ua8e0-\ua8f1\ua900-\ua909\ua926-\ua92d\ua947-\ua953\ua980-\ua983\ua9b3-\ua9c0\ua9d0-\ua9d9\ua9e5\ua9f0-\ua9f9\uaa29-\uaa36\uaa43\uaa4c\uaa4d\uaa50-\uaa59\uaa7b-\uaa7d\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uaaeb-\uaaef\uaaf5\uaaf6\uabe3-\uabea\uabec\uabed\uabf0-\uabf9\ufb1e\ufe00-\ufe0f\ufe20-\ufe2d\ufe33\ufe34\ufe4d-\ufe4f\uff10-\uff19\uff3f";
+
+const nonASCIIidentifierStart = new RegExp("[" + nonASCIIidentifierStartChars + "]");
+const nonASCIIidentifier = new RegExp("[" + nonASCIIidentifierStartChars + nonASCIIidentifierChars + "]");
+
+nonASCIIidentifierStartChars = nonASCIIidentifierChars = null;
+
+// These are a run-length and offset encoded representation of the
+// >0xffff code points that are a valid part of identifiers. The
+// offset starts at 0x10000, and each pair of numbers represents an
+// offset to the next range, and then a size of the range.
+let astralIdentifierStartCodes = [
+	0, 11, 2, 25, 2, 18, 2, 1, 2, 14, 3, 13, 35, 122, 70, 52, 268, 28, 4, 48, 48, 31, 17, 26, 6, 37, 11, 29, 3, 35, 5,
+	7, 2, 4, 43, 157, 99, 39, 9, 51, 157, 310, 10, 21, 11, 7, 153, 5, 3, 0, 2, 43, 2, 1, 4, 0, 3, 22, 11, 22, 10, 30,
+	98, 21, 11, 25, 71, 55, 7, 1, 65, 0, 16, 3, 2, 2, 2, 26, 45, 28, 4, 28, 36, 7, 2, 27, 28, 53, 11, 21, 11, 18, 14,
+	17, 111, 72, 955, 52, 76, 44, 33, 24, 27, 35, 42, 34, 4, 0, 13, 47, 15, 3, 22, 0, 38, 17, 2, 24, 133, 46, 39, 7,
+	3, 1, 3, 21, 2, 6, 2, 1, 2, 4, 4, 0, 32, 4, 287, 47, 21, 1, 2, 0, 185, 46, 82, 47, 21, 0, 60, 42, 502, 63, 32, 0,
+	449, 56, 1288, 920, 104, 110, 2962, 1070, 13266, 568, 8, 30, 114, 29, 19, 47, 17, 3, 32, 20, 6, 18, 881, 68, 12,
+	0, 67, 12, 16481, 1, 3071, 106, 6, 12, 4, 8, 8, 9, 5991, 84, 2, 70, 2, 1, 3, 0, 3, 1, 3, 3, 2, 11, 2, 0, 2, 6, 2,
+	64, 2, 3, 3, 7, 2, 6, 2, 27, 2, 3, 2, 4, 2, 0, 4, 6, 2, 339, 3, 24, 2, 24, 2, 30, 2, 24, 2, 30, 2, 24, 2, 30, 2,
+	24, 2, 30, 2, 24, 2, 7, 4149, 196, 1340, 3, 2, 26, 2, 1, 2, 0, 3, 0, 2, 9, 2, 3, 2, 0, 2, 0, 7, 0, 5, 0, 2, 0, 2,
+	0, 2, 2, 2, 1, 2, 0, 3, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 1, 2, 0, 3, 3, 2, 6, 2, 3, 2, 3, 2, 0, 2, 9, 2, 16, 6, 2, 2,
+	4, 2, 16, 4421, 42710, 42, 4148, 12, 221, 16355, 541
+];
+let astralIdentifierCodes = [
+	509, 0, 227, 0, 150, 4, 294, 9, 1368, 2, 2, 1, 6, 3, 41, 2, 5, 0, 166, 1, 1306, 2, 54, 14, 32, 9, 16, 3, 46, 10,
+	54, 9, 7, 2, 37, 13, 2, 9, 52, 0, 13, 2, 49, 13, 16, 9, 83, 11, 168, 11, 6, 9, 8, 2, 57, 0, 2, 6, 3, 1, 3, 2, 10,
+	0, 11, 1, 3, 6, 4, 4, 316, 19, 13, 9, 214, 6, 3, 8, 112, 16, 16, 9, 82, 12, 9, 9, 535, 9, 20855, 9, 135, 4, 60, 6,
+	26, 9, 1016, 45, 17, 3, 19723, 1, 5319, 4, 4, 5, 9, 7, 3, 6, 31, 3, 149, 2, 1418, 49, 4305, 6, 792618, 239
+];
+
+// This has a complexity linear to the value of the code. The
+// assumption is that looking up astral identifier characters is
+// rare.
+function isInAstralSet(code, set) {
+	let pos = 0x10000;
+	for (let i = 0; i < set.length; i += 2) {
+		pos += set[i];
+		if (pos > code) return false;
+
+		pos += set[i + 1];
+		if (pos >= code) return true;
+	}
+}
+
+// Test whether a given character code starts an identifier.
+
+function isIdentifierStart(code) {
+	let c = code.charCodeAt(0);
+	if (c < 65) return c === 36;
+	if (c < 91) return true;
+	if (c < 97) return c === 95;
+	if (c < 123) return true;
+	if (c <= 0xffff) return c >= 0xaa && nonASCIIidentifierStart.test(String.fromCharCode(c));
+	return isInAstralSet(c, astralIdentifierStartCodes);
+}
+
+// Test whether a given character is part of an identifier.
+
+function isIdentifierChar(code) {
+	let l = code.length;
+	while (l--) {
+		let ch = code.charCodeAt(code.length - l);
+		return validationChar(ch) || ch === 0x24 /* $ */ || ch === 0x5F /* _ */ || ch === 0x200C /* <ZWNJ> */ || ch === 0x200D; /* <ZWJ> */
+	}
+}
+
+function validationChar(code) {
+	if (code < 48) return code === 36;
+	if (code < 58) return true;
+	if (code < 65) return false;
+	if (code < 91) return true;
+	if (code < 97) return code === 95;
+	if (code < 123) return true;
+	if (code <= 0xffff) return code >= 0xaa && nonASCIIidentifier.test(String.fromCharCode(code));
+	return isInAstralSet(code, astralIdentifierStartCodes) || isInAstralSet(code, astralIdentifierCodes);
+}
+
+module.exports = {
+	isIdentifierChar,
+	isIdentifierStart,
+	isKeyword
+};

lib/utils/validate-identifier.test.js

@@ -0,0 +1,35 @@
+"use strict";
+
+const validateIdentifier = require("./validate-identifier");
+
+describe("validate-identifier", () => {
+	it("should return true for reserved keyword", () => {
+		const l = "while";
+		expect(validateIdentifier.isKeyword(l)).toBe(true);
+	});
+
+	it("should return false for unreserved keyword", () => {
+		const l = "foo";
+		expect(validateIdentifier.isKeyword(l)).toBe(false);
+	});
+
+	it("should retrun false if literal is not in U+200C zero width non-joiner, U+200D zero width joiner, or any symbol with the Unicode derived core property ID_Continue", () => {
+		const l = "\u00A9";
+		expect(validateIdentifier.isIdentifierChar(l)).toBe(false);
+	});
+
+	it("should retrun true if literal is in U+200C zero width non-joiner, U+200D zero width joiner, or any symbol with the Unicode derived core property ID_Continue", () => {
+		const l = "foo$bar";
+		expect(validateIdentifier.isIdentifierChar(l)).toBe(true);
+	});
+
+	it("should return true if literal name starts with $, _ or any symbol with the unicode derived core property ID_Start", () => {
+		const l = "$foo";
+		expect(validateIdentifier.isIdentifierStart(l)).toBe(true);
+	});
+
+	it("should return false if literal name does not starts with $, _ or any symbol with the unicode derived core property ID_Start", () => {
+		const l = "^bar";
+		expect(validateIdentifier.isIdentifierStart(l)).toBe(false);
+	});
+});