babel-core: add options for different parser/generator (#3561)

* babel-core: add options for different parser/generator

* test for experiemental plugins, other babylon options

* fix passing options into parser

* Fix when no code is provided

* fixup tests

* fix tests again

* use filename and fallback to cwd

packages/babel-core/src/transformation/file/index.js

@@ -21,6 +21,8 @@ import * as util from  "../../util";
 import path from "path";
 import * as t from "babel-types";
 
+import resolve from "../../helpers/resolve";
+
 import blockHoistPlugin from "../internal-plugins/block-hoist";
 import shadowFunctionsPlugin from "../internal-plugins/shadow-functions";
 
@@ -411,8 +413,35 @@ export default class File extends Store {
   }
 
   parse(code: string) {
+    let parseCode = parse;
+    let parserOpts = this.opts.parserOpts || this.parserOpts;
+
+    if (parserOpts) {
+      parserOpts = Object.assign({}, this.parserOpts, parserOpts);
+
+      if (parserOpts.parser) {
+        if (typeof parserOpts.parser === "string") {
+          let dirname = path.dirname(this.opts.filename) || process.cwd();
+          let parser = resolve(parserOpts.parser, dirname);
+          if (parser) {
+            parseCode = require(parser).parse;
+          } else {
+            throw new Error(`Couldn't find parser ${parserOpts.parser} with "parse" method relative to directory ${dirname}`);
+          }
+        } else {
+          parseCode = parserOpts.parser;
+        }
+
+        parserOpts.parser = {
+          parse(source) {
+            return parse(source, parserOpts);
+          }
+        };
+      }
+    }
+
     this.log.debug("Parse start");
-    let ast = parse(code, this.parserOpts);
+    let ast = parseCode(code, parserOpts);
     this.log.debug("Parse stop");
     return ast;
   }
@@ -573,9 +602,24 @@ export default class File extends Store {
     let result: BabelFileResult = { ast };
     if (!opts.code) return this.makeResult(result);
 
+    let gen = generate;
+    if (opts.generatorOpts.generator) {
+      gen = opts.generatorOpts.generator;
+
+      if (typeof gen === "string") {
+        let dirname = path.dirname(this.opts.filename) || process.cwd();
+        let generator = resolve(gen, dirname);
+        if (generator) {
+          gen = require(generator).print;
+        } else {
+          throw new Error(`Couldn't find generator ${gen} with "print" method relative to directory ${dirname}`);
+        }
+      }
+    }
+
     this.log.debug("Generation start");
 
-    let _result = generate(ast, opts, this.code);
+    let _result = gen(ast, opts.generatorOpts ? Object.assign(opts, opts.generatorOpts) : opts, this.code);
     result.code = _result.code;
     result.map  = _result.map;
 

packages/babel-core/src/transformation/file/options/config.js

@@ -198,4 +198,16 @@ module.exports = {
     default: false,
     hidden: true,
   },
+
+  // Deprecate top level parserOpts
+  parserOpts: {
+    description: "Options to pass into the parser, or to change parsers (parserOpts.parser)",
+    default: false
+  },
+
+  // Deprecate top level generatorOpts
+  generatorOpts: {
+    description: "Options to pass into the generator, or to change generators (generatorOpts.generator)",
+    default: false
+  }
 };

packages/babel-core/test/api.js

@@ -5,6 +5,7 @@ var sourceMap            = require("source-map");
 var assert               = require("assert");
 var File                 = require("../lib/transformation/file").default;
 var Plugin               = require("../lib/transformation/plugin");
+var generator            = require("babel-generator").default;
 
 function assertIgnored(result) {
   assert.ok(result.ignored);
@@ -23,6 +24,77 @@ function transformAsync(code, opts) {
   };
 }
 
+suite("parser and generator options", function() {
+  var recast = {
+    parse: function(code, opts) {
+      return opts.parser.parse(code);
+    },
+    print: function(ast) {
+      return generator(ast);
+    }
+  };
+
+  function newTransform(string) {
+    return babel.transform(string, {
+      parserOpts: {
+        parser: recast.parse,
+        plugins: ["flow"],
+        allowImportExportEverywhere: true
+      },
+      generatorOpts: {
+        generator: recast.print
+      }
+    });
+  }
+
+  test("options", function() {
+    var string = "original;";
+    assert.deepEqual(newTransform(string).ast, babel.transform(string).ast);
+    assert.equal(newTransform(string).code, string);
+  });
+
+  test("experimental syntax", function() {
+    var experimental = "var a: number = 1;";
+
+    assert.deepEqual(newTransform(experimental).ast, babel.transform(experimental, {
+      parserOpts: {
+        plugins: ["flow"]
+      }
+    }).ast);
+    assert.equal(newTransform(experimental).code, experimental);
+
+    function newTransformWithPlugins(string) {
+      return babel.transform(string, {
+        plugins: [__dirname + "/../../babel-plugin-syntax-flow"],
+        parserOpts: {
+          parser: recast.parse
+        },
+        generatorOpts: {
+          generator: recast.print
+        }
+      });
+    }
+
+    assert.deepEqual(newTransformWithPlugins(experimental).ast, babel.transform(experimental, {
+      parserOpts: {
+        plugins: ["flow"]
+      }
+    }).ast);
+    assert.equal(newTransformWithPlugins(experimental).code, experimental);
+  });
+
+  test("other options", function() {
+    var experimental = "if (true) {\n  import a from 'a';\n}";
+
+    assert.notEqual(newTransform(experimental).ast, babel.transform(experimental, {
+      parserOpts: {
+        allowImportExportEverywhere: true
+      }
+    }).ast);
+    assert.equal(newTransform(experimental).code, experimental);
+  });
+});
+
 suite("api", function () {
   test("analyze", function () {
     assert.equal(babel.analyse("foobar;").marked.length, 0);

packages/babel-generator/src/index.js

@@ -93,6 +93,11 @@ function normalizeOptions(code, opts, tokens): Format {
  * Determine if input code uses more single or double quotes.
  */
 function findCommonStringDelimiter(code, tokens) {
+  const DEFAULT_STRING_DELIMITER = "double";
+  if (!code) {
+    return DEFAULT_STRING_DELIMITER;
+  }
+
   let occurences = {
     single: 0,
     double: 0
@@ -117,7 +122,7 @@ function findCommonStringDelimiter(code, tokens) {
   if (occurences.single > occurences.double) {
     return "single";
   } else {
-    return "double";
+    return DEFAULT_STRING_DELIMITER;
   }
 }