module: CJS exports detection for modules with __esModule export

deps/cjs-module-lexer/.gitignore

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+node_modules
+*.lock
+test
+.*
+Makefile
+bench
+build.js
+include-wasm
+include
+lib
+src

deps/cjs-module-lexer/LICENSE

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+MIT License
+-----------
+
+Copyright (C) 2018-2020 Guy Bedford
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

deps/cjs-module-lexer/README.md

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+# CJS Module Lexer
+
+[![Build Status][travis-image]][travis-url]
+
+A [very fast](#benchmarks) JS CommonJS module syntax lexer used to detect the most likely list of named exports of a CommonJS module.
+
+Outputs the list of named exports (`exports.name = ...`), whether the `__esModule` interop flag is used, and possible module reexports (`module.exports = require('...')`).
+
+For an example of the performance, Angular 1 (720KiB) is fully parsed in 5ms, in comparison to the fastest JS parser, Acorn which takes over 100ms.
+
+_Comprehensively handles the JS language grammar while remaining small and fast. - ~10ms per MB of JS cold and ~5ms per MB of JS warm, [see benchmarks](#benchmarks) for more info._
+
+### Usage
+
+```
+npm install cjs-module-lexer
+```
+
+For use in CommonJS:
+
+```js
+const { init, parse } = require('cjs-module-lexer');
+
+(async () => {
+  // Init must be called first.
+  await init();
+
+  const { exports, reexports, esModule } = parse(`
+    // named exports detection
+    module.exports.a = 'a';
+    (function () {
+      exports.b = 'b';
+    })();
+    Object.defineProperty(exports, 'c', { value: 'c' });
+    /* exports.d = 'not detected'; */
+
+    // reexports detection
+    if (maybe) module.exports = require('./dep1.js');
+    if (another) module.exports = require('./dep2.js');
+
+    // literal exports assignments
+    module.exports = { a, b: c, d, 'e': f }
+
+    // __esModule detection
+    Object.defineProperty(module.exports, '__esModule', { value: true })
+  `);
+
+  // exports === ['a', 'b', 'c', '__esModule']
+  // reexports === ['./dep1.js', './dep2.js']
+})();
+```
+
+### Grammar
+
+CommonJS exports matches are run against the source token stream.
+
+The token grammar is:
+
+```
+IDENTIFIER: As defined by ECMA-262, without support for identifier `\` escapes, filtered to remove strict reserved words:
+            "implements", "interface", "let", "package", "private", "protected", "public", "static", "yield", "enum"
+
+STRING_LITERAL: A `"` or `'` bounded ECMA-262 string literal.
+
+IDENTIFIER_STRING: ( `"` IDENTIFIER `"` | `'` IDENTIFIER `'` )
+
+COMMENT_SPACE: Any ECMA-262 whitespace, ECMA-262 block comment or ECMA-262 line comment
+
+MODULE_EXPORTS: `module` COMMENT_SPACE `.` COMMENT_SPACE `exports`
+
+EXPORTS_IDENTIFIER: MODULE_EXPORTS_IDENTIFIER | `exports`
+
+EXPORTS_DOT_ASSIGN: EXPORTS_IDENTIFIER COMMENT_SPACE `.` COMMENT_SPACE IDENTIFIER COMMENT_SPACE `=`
+
+EXPORTS_LITERAL_COMPUTED_ASSIGN: EXPORTS_IDENTIFIER COMMENT_SPACE `[` COMMENT_SPACE IDENTIFIER_STRING COMMENT_SPACE `]` COMMENT_SPACE `=`
+
+EXPORTS_LITERAL_PROP: (IDENTIFIER (COMMENT_SPACE `:` COMMENT_SPACE IDENTIFIER)?) | (IDENTIFIER_STRING COMMENT_SPACE `:` COMMENT_SPACE IDENTIFIER)
+
+EXPORTS_MEMBER: EXPORTS_DOT_ASSIGN | EXPORTS_LITERAL_COMPUTED_ASSIGN
+
+EXPORTS_DEFINE: `Object` COMMENT_SPACE `.` COMMENT_SPACE `defineProperty COMMENT_SPACE `(` EXPORTS_IDENTIFIER COMMENT_SPACE `,` COMMENT_SPACE IDENTIFIER_STRING
+
+EXPORTS_LITERAL: MODULE_EXPORTS COMMENT_SPACE `=` COMMENT_SPACE `{` COMMENT_SPACE (EXPORTS_LITERAL_PROP COMMENT_SPACE `,` COMMENT_SPACE)+ `}`
+
+REQUIRE: `require` COMMENT_SPACE `(` COMMENT_SPACE STRING_LITERAL COMMENT_SPACE `)`
+
+EXPORTS_ASSIGN: (`var` | `const` | `let`) IDENTIFIER `=` REQUIRE
+
+MODULE_EXPORTS_ASSIGN: MODULE_EXPORTS COMMENT_SPACE `=` COMMENT_SPACE REQUIRE
+
+EXPORT_STAR: (`__export` | `__exportStar`) `(` REQUIRE
+
+EXPORT_STAR_LIB: `Object.keys(` IDENTIFIER$1 `).forEach(function (` IDENTIFIER$2 `) {`
+  (
+    `if (` IDENTIFIER$2 `===` ( `'default'` | `"default"` ) `||` IDENTIFIER$2 `===` ( '__esModule' | `"__esModule"` ) `) return` `;`? |
+    `if (` IDENTIFIER$2 `!==` ( `'default'` | `"default"` ) `)`
+  )
+  (
+    EXPORTS_IDENTIFIER `[` IDENTIFIER$2 `] =` IDENTIFIER$1 `[` IDENTIFIER$2 `]` `;`? |
+    `Object.defineProperty(` EXPORTS_IDENTIFIER `, ` IDENTIFIER$2 `, { enumerable: true, get: function () { return ` IDENTIFIER$1 `[` IDENTIFIER$2 `]` `;`? } })` `;`?
+  )
+  `})`
+```
+
+* The returned export names are the matched `IDENTIFIER` and `IDENTIFIER_STRING` slots for all `EXPORTS_MEMBER`, `EXPORTS_DEFINE` and `EXPORTS_LITERAL` matches.
+* The reexport specifiers are taken to be the `STRING_LITERAL` slots of all top-level `MODULE_EXPORTS_ASSIGN` and `EXPORT_STAR` `REQUIRE` matches as well as all `EXPORTS_ASSIGN` matches whose `IDENTIFIER` also matches the first `IDENTIFIER` in `EXPORT_STAR_LIB`
+
+### Not Supported
+
+#### No scope analysis:
+
+```js
+// "a" WILL be detected as an export
+(function (exports) {
+  exports.a = 'a'; 
+})(notExports);
+
+// "b" WONT be detected as an export
+(function (m) {
+  m.a = 'a';
+})(exports);
+```
+
+#### `module.exports` require assignment only handled at the base-level
+
+```js
+// OK
+module.exports = require('./a.js');
+
+// OK
+if (condition)
+  module.exports = require('./b.js');
+
+// NOT OK -> nested top-level detections not implemented
+if (condition) {
+  module.exports = require('./c.js');
+}
+(function () {
+  module.exports = require('./d.js');
+})();
+```
+
+#### No object expression parsing
+
+```js
+// These WONT be detected as exports
+Object.defineProperties(exports, {
+  a: { value: 'a' },
+  b: { value: 'b' }
+});
+
+module.exports = {
+  // These WILL be detected as exports
+  a: a,
+  b: b,
+
+  // This WILL be detected as an export
+  e: require('d'),
+
+  // These WONT be detected as exports
+  // because the object parser stops on the non-identifier
+  // expression "require('d')"
+  f: 'f'
+}
+```
+
+#### Only specific transpiler-style star export patterns match
+
+```js
+// './x' detected as star export
+var x = require('./x');
+Object.keys(x).forEach(function (k) {
+	if (k !== 'default') Object.defineProperty(exports, k, {
+		enumerable: true,
+		get: function () {
+			return x[k];
+		}
+	});
+});
+
+// './y' detected as star export
+let y = require('./y');
+Object.keys(y).forEach(function (kk) {
+	if (kk !== 'default') exports[kk] = y[kk];
+});
+
+// './z' NOT detected as star export
+let z = require('./z');
+for (const key of Object.keys(x)) {
+  exports[key] = x[key];
+}
+```
+
+These patterns can be updated over time to match modern transpiler outputs.
+
+### Environment Support
+
+Node.js 10+, and [all browsers with Web Assembly support](https://caniuse.com/#feat=wasm).
+
+### Grammar Support
+
+* Token state parses all line comments, block comments, strings, template strings, blocks, parens and punctuators.
+* Division operator / regex token ambiguity is handled via backtracking checks against punctuator prefixes, including closing brace or paren backtracking.
+* Always correctly parses valid JS source, but may parse invalid JS source without errors.
+
+### Benchmarks
+
+Benchmarks can be run with `npm run bench`.
+
+Current results:
+
+```
+Cold Run, All Samples
+test/samples/*.js (3057 KiB)
+> 24ms
+
+Warm Runs (average of 25 runs)
+test/samples/angular.js (719 KiB)
+> 5.12ms
+test/samples/angular.min.js (188 KiB)
+> 3.04ms
+test/samples/d3.js (491 KiB)
+> 4.08ms
+test/samples/d3.min.js (274 KiB)
+> 2.04ms
+test/samples/magic-string.js (34 KiB)
+> 0ms
+test/samples/magic-string.min.js (20 KiB)
+> 0ms
+test/samples/rollup.js (902 KiB)
+> 5.92ms
+test/samples/rollup.min.js (429 KiB)
+> 3.08ms
+
+Warm Runs, All Samples (average of 25 runs)
+test/samples/*.js (3057 KiB)
+> 17.4ms
+```
+
+### Building
+
+To build download the WASI SDK from https://github.com/CraneStation/wasi-sdk/releases.
+
+The Makefile assumes that the `clang` in PATH corresponds to LLVM 8 (provided by WASI SDK as well, or a standard clang 8 install can be used as well), and that `../wasi-sdk-6` contains the SDK as extracted above, which is important to locate the WASI sysroot.
+
+The build through the Makefile is then run via `make lib/lexer.wasm`, which can also be triggered via `npm run build-wasm` to create `dist/lexer.js`.
+
+On Windows it may be preferable to use the Linux subsystem.
+
+After the Web Assembly build, the CJS build can be triggered via `npm run build`.
+
+Optimization passes are run with [Binaryen](https://github.com/WebAssembly/binaryen) prior to publish to reduce the Web Assembly footprint.
+
+### License
+
+MIT
+
+[travis-url]: https://travis-ci.org/guybedford/es-module-lexer
+[travis-image]: https://travis-ci.org/guybedford/es-module-lexer.svg?branch=master

deps/cjs-module-lexer/include/cjs-module-lexer.h

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+#ifndef __CJS_MODULE_LEXER_H__
+#define __CJS_MODULE_LEXER_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+struct Slice {
+  const uint16_t* start;
+  const uint16_t* end;
+};
+typedef struct Slice Slice;
+
+struct StarExportBinding {
+  const uint16_t* specifier_start;
+  const uint16_t* specifier_end;
+  const uint16_t* id_start;
+  const uint16_t* id_end;
+};
+typedef struct StarExportBinding StarExportBinding;
+
+void bail (uint32_t err);
+
+bool parseCJS (uint16_t* source, uint32_t sourceLen, void (*addExport)(const uint16_t*, const uint16_t*), void (*addReexport)(const uint16_t*, const uint16_t*));
+
+void tryBacktrackAddStarExportBinding (uint16_t* pos);
+bool tryParseRequire (bool directStarExport);
+void tryParseLiteralExports ();
+bool readExportsOrModuleDotExports (uint16_t ch);
+void tryParseModuleExportsDotAssign ();
+void tryParseExportsDotAssign (bool assign);
+void tryParseObjectDefineOrKeys ();
+bool identifier (uint16_t ch);
+
+void throwIfImportStatement ();
+void throwIfExportStatement ();
+
+void readImportString (const uint16_t* ss, uint16_t ch);
+uint16_t readExportAs (uint16_t* startPos, uint16_t* endPos);
+
+uint16_t commentWhitespace ();
+void singleQuoteString ();
+void doubleQuoteString ();
+void regularExpression ();
+void templateString ();
+void blockComment ();
+void lineComment ();
+
+uint16_t readToWsOrPunctuator (uint16_t ch);
+
+uint32_t fullCharCodeAtLast (uint16_t* pos);
+bool isIdentifierStart (uint32_t code);
+bool isIdentifierChar (uint32_t code);
+int charCodeByteLen (uint32_t ch);
+
+bool isBr (uint16_t c);
+bool isBrOrWs (uint16_t c);
+bool isBrOrWsOrPunctuator (uint16_t c);
+bool isBrOrWsOrPunctuatorNotDot (uint16_t c);
+
+bool str_eq2 (uint16_t* pos, uint16_t c1, uint16_t c2);
+bool str_eq3 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3);
+bool str_eq4 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4);
+bool str_eq5 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5);
+bool str_eq6 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6);
+bool str_eq7 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6, uint16_t c7);
+bool str_eq9 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6, uint16_t c7, uint16_t c8, uint16_t c9);
+bool str_eq10 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6, uint16_t c7, uint16_t c8, uint16_t c9, uint16_t c10);
+bool str_eq13 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6, uint16_t c7, uint16_t c8, uint16_t c9, uint16_t c10, uint16_t c11, uint16_t c12, uint16_t c13);
+bool str_eq18 (uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6, uint16_t c7, uint16_t c8, uint16_t c9, uint16_t c10, uint16_t c11, uint16_t c12, uint16_t c13, uint16_t c14, uint16_t c15, uint16_t c16, uint16_t c17, uint16_t c18);
+
+bool readPrecedingKeyword2(uint16_t* pos, uint16_t c1, uint16_t c2);
+bool readPrecedingKeyword3(uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3);
+bool readPrecedingKeyword4(uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4);
+bool readPrecedingKeyword5(uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5);
+bool readPrecedingKeyword6(uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6);
+bool readPrecedingKeyword7(uint16_t* pos, uint16_t c1, uint16_t c2, uint16_t c3, uint16_t c4, uint16_t c5, uint16_t c6, uint16_t c7);
+
+bool keywordStart (uint16_t* pos);
+bool isExpressionKeyword (uint16_t* pos);
+bool isParenKeyword (uint16_t* pos);
+bool isPunctuator (uint16_t charCode);
+bool isExpressionPunctuator (uint16_t charCode);
+bool isExpressionTerminator (uint16_t* pos);
+
+void nextChar (uint16_t ch);
+void nextCharSurrogate (uint16_t ch);
+uint16_t readChar ();
+
+void syntaxError ();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __CJS_MODULE_LEXER_H__ */