Add bigint support

Author: goto-bus-stop

LICENSE.md

@@ -14,6 +14,32 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 
+## acorn-bigint
+
+The code in the `lib/bigint` folder is compiled from code licensed as MIT:
+
+> Copyright (C) 2017-2018 by Adrian Heine
+>
+> 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.
+
+Find the source code at https://github.com/acornjs/acorn-bigint.
+
 ## acorn-import-meta
 
 The code in the `lib/import-meta` folder is compiled from code licensed as MIT:

build.js

@@ -17,5 +17,6 @@ function compile (name, output) { // eslint-disable-line no-unused-vars
   fs.writeFileSync(path.join(__dirname, output), HEADER + result.code, 'utf8')
 }
 
+compile('acorn-bigint', './lib/bigint/index.js')
 compile('acorn-import-meta', './lib/import-meta/index.js')
 compile('./lib/dynamic-import/source', './lib/dynamic-import/index.js')

index.js

@@ -2,7 +2,8 @@ var acorn = require('acorn')
 var xtend = require('xtend')
 
 var CJSParser = acorn.Parser
-var ESModulesParser = acorn.Parser
+  .extend(require('./lib/bigint'))
+var ESModulesParser = CJSParser
   .extend(require('./lib/dynamic-import'))
   .extend(require('./lib/import-meta'))
 

lib/bigint/index.js

@@ -0,0 +1,65 @@
+/* Generated by `npm run build`, do not edit! */
+
+"use strict"
+
+var acorn = require("acorn")
+var tt = acorn.tokTypes
+var isIdentifierStart = acorn.isIdentifierStart
+
+module.exports = function(Parser) {
+  return (function (Parser) {
+    function anonymous () {
+      Parser.apply(this, arguments);
+    }
+
+    if ( Parser ) anonymous.__proto__ = Parser;
+    anonymous.prototype = Object.create( Parser && Parser.prototype );
+    anonymous.prototype.constructor = anonymous;
+
+    anonymous.prototype.parseLiteral = function parseLiteral (value) {
+      var node = Parser.prototype.parseLiteral.call(this, value)
+      if (node.raw.charCodeAt(node.raw.length - 1) == 110) { node.bigint = node.raw }
+      return node
+    };
+
+    anonymous.prototype.readRadixNumber = function readRadixNumber (radix) {
+      var start = this.pos
+      this.pos += 2 // 0x
+      var val = this.readInt(radix)
+      if (val === null) { this.raise(this.start + 2, ("Expected number in radix " + radix)) }
+      if (this.input.charCodeAt(this.pos) == 110) {
+        var str = this.input.slice(start, this.pos)
+        val = typeof BigInt !== "undefined" ? BigInt(str) : null
+        ++this.pos
+      } else if (isIdentifierStart(this.fullCharCodeAtPos())) { this.raise(this.pos, "Identifier directly after number") }
+      return this.finishToken(tt.num, val)
+    };
+
+    anonymous.prototype.readNumber = function readNumber (startsWithDot) {
+      var start = this.pos
+
+      // Not an int
+      if (startsWithDot) { return Parser.prototype.readNumber.call(this, startsWithDot) }
+
+      // Legacy octal
+      if (this.input.charCodeAt(start) === 48 && this.input.charCodeAt(start + 1) !== 110) {
+        return Parser.prototype.readNumber.call(this, startsWithDot)
+      }
+
+      if (this.readInt(10) === null) { this.raise(start, "Invalid number") }
+
+      // Not a BigInt, reset and parse again
+      if (this.input.charCodeAt(this.pos) != 110) {
+        this.pos = start
+        return Parser.prototype.readNumber.call(this, startsWithDot)
+      }
+
+      var str = this.input.slice(start, this.pos)
+      var val = typeof BigInt !== "undefined" && BigInt.parseInt ? BigInt.parseInt(str) : null
+      ++this.pos
+      return this.finishToken(tt.num, val)
+    };
+
+    return anonymous;
+  }(Parser))
+}

package.json

@@ -12,6 +12,7 @@
     "xtend": "^4.0.1"
   },
   "devDependencies": {
+    "acorn-bigint": "^0.3.0",
     "acorn-import-meta": "^0.3.0",
     "buble": "^0.19.3",
     "mkdirp": "^0.5.1",

test/index.js

@@ -17,7 +17,7 @@ test('parses object spread syntax', function (t) {
 
 test('does not change main acorn module', function (t) {
   t.throws(function () {
-    baseAcorn.parse('var a = { ...b }')
+    baseAcorn.parse('var a = 10n')
   })
   t.end()
 })
@@ -66,7 +66,7 @@ test('supports optional catch', function (t) {
   t.end()
 })
 
-test.skip('supports bigint', function (t) {
+test('supports bigint', function (t) {
   t.doesNotThrow(function () {
     acorn.parse('50n ** 50n')
   })