Use recast for parsing and formatting (#44)

#44

.eslintrc.js

@@ -0,0 +1,6 @@
+module.exports = {
+  extends: ['eslint-config-fusion'],
+  env: {
+    'node': true 
+  }
+};

Dockerfile

@@ -5,4 +5,5 @@ WORKDIR /dubstep-core
 COPY . .
 
 RUN yarn
+RUN yarn lint
 RUN yarn test

README.md

@@ -301,15 +301,10 @@ visitJsImport(
 ```js
 import {generateJs} from '@dubstep/core';
 
-generateJs = (path: NodePath, options: GenerateJsObject) => string;
-type GenerateJsOptions = ?{
-  formatter: ?('babel' | 'prettier'),
-  formatterOptions: ?Object,
-};
+generateJs = (path: NodePath) => string;
 ```
 
-Converts a Program `NodePath` into a Javascript code string. The default formatter is `prettier`. The `formatterOptions` object should be [prettier options map](https://prettier.io/docs/en/options.html) or a [babel generator options map](https://babeljs.io/docs/en/next/babel-generator.html#options) depending on which `formatter` is specified.
-
+Converts a Program `NodePath` into a Javascript code string.
 A `NodePath` can be obtained from `withJsFile`, `withJsFiles` or `parseJs`.
 
 ##### insertJsAfter

package.json

@@ -14,6 +14,7 @@
     "dev": "npm-watch | grep --invert-match nodemon",
     "build": "babel src -d dist -q",
     "test": "jest",
+    "lint": "eslint src/",
     "cover": "jest --coverage",
     "flow": "flow check || true",
     "prepare": "babel src -d dist -s"
@@ -39,21 +40,18 @@
     }
   },
   "dependencies": {
-    "@babel/generator": "^7.1.5",
     "@babel/parser": "^7.1.5",
     "@babel/template": "^7.1.2",
     "@babel/traverse": "^7.1.5",
     "@babel/types": "^7.1.5",
-    "eslint": "^5.9.0",
-    "eslint-config-prettier": "^3.1.0",
-    "eslint-plugin-prettier": "^3.0.0",
     "execa": "^1.0.0",
     "flow-coverage-report": "^0.6.0",
     "fs-extra": "^7.0.1",
     "globby": "^8.0.1",
     "ini": "^1.3.5",
     "isomorphic-git": "^0.39.3",
-    "prettier": "^1.15.1"
+    "prettier": "^1.15.1",
+    "recast": "^0.16.0"
   },
   "devDependencies": {
     "@babel/cli": "7.1.5",
@@ -65,6 +63,15 @@
     "babel-eslint": "10.0.1",
     "babel-jest": "23.6.0",
     "babel-preset-flow": "6.23.0",
+    "eslint": "^5.9.0",
+    "eslint-config-fusion": "^4.0.0",
+    "eslint-config-prettier": "^3.1.0",
+    "eslint-plugin-cup": "^2.0.0",
+    "eslint-plugin-flowtype": "^3.2.0",
+    "eslint-plugin-import": "^2.14.0",
+    "eslint-plugin-jest": "^22.0.0",
+    "eslint-plugin-prettier": "^3.0.0",
+    "eslint-plugin-react": "^7.11.1",
     "flow-bin": "0.86.0",
     "jest": "23.6.0",
     "markdown-it": "^8.4.2",

src/core/index.test.js

@@ -25,6 +25,7 @@ THE SOFTWARE.
 import * as API from './index.js';
 import markdown from 'markdown-it';
 import fs from 'fs';
+
 const {Stepper, step, StepperError} = API;
 
 test('test', () => {

src/utils/ensure-js-imports.test.js

@@ -30,51 +30,57 @@ test('ensureJsImports', () => {
   const path = parseJs('');
   const vars = ensureJsImports(path, `import foo, {bar} from 'bar';`);
   const code = generateJs(path);
-  expect(code.trim()).toEqual(`import foo, { bar } from 'bar';`);
+  expect(code.trim()).toMatchInlineSnapshot(`"import foo, {bar} from 'bar';"`);
   expect(vars).toEqual([{default: 'foo', bar: 'bar'}]);
 });
 
 test('ensureJsImports after', () => {
   const path = parseJs(`import 'x';`);
   const vars = ensureJsImports(path, `import foo, {bar} from 'bar';`);
   const code = generateJs(path);
-  expect(code.trim()).toEqual(`import 'x';\nimport foo, { bar } from 'bar';`);
+  expect(code.trim()).toMatchInlineSnapshot(
+    `"import 'x';import foo, {bar} from 'bar';"`
+  );
   expect(vars).toEqual([{default: 'foo', bar: 'bar'}]);
 });
 
 test('ensureJsImports before', () => {
   const path = parseJs(`const a = 1;`);
   const vars = ensureJsImports(path, `import foo, {bar} from 'bar';`);
   const code = generateJs(path);
-  expect(code.trim()).toEqual(`import foo, { bar } from 'bar';\nconst a = 1;`);
+  expect(code.trim()).toMatchInlineSnapshot(
+    `"import foo, {bar} from 'bar';const a = 1;"`
+  );
   expect(vars).toEqual([{default: 'foo', bar: 'bar'}]);
 });
 
 test('merge', () => {
   const path = parseJs(`import {x} from 'foo'`);
   const vars = ensureJsImports(path, `import foo, {bar} from 'foo';`);
   const code = generateJs(path);
-  expect(code.trim()).toEqual(`import foo, { x, bar } from 'foo';`);
+  expect(code.trim()).toMatchInlineSnapshot(
+    `"import foo, { x, bar } from 'foo';"`
+  );
   expect(vars).toEqual([{default: 'foo', x: 'x', bar: 'bar'}]);
 });
 
 test('retain default', () => {
   const path = parseJs(`import foo from 'foo'`);
   const vars = ensureJsImports(path, `import wildcard from 'foo';`);
   const code = generateJs(path);
-  expect(code.trim()).toEqual(`import foo from 'foo';`);
+  expect(code.trim()).toMatchInlineSnapshot(`"import foo from 'foo'"`);
   expect(vars).toEqual([{default: 'foo'}]);
 });
 
 test('multiple', () => {
   const path = parseJs(`import foo from 'foo';import bar from 'bar'`);
   const vars = ensureJsImports(
     path,
-    `import wildcard from 'foo';import another, {x} from 'bar';`,
+    `import wildcard from 'foo';import another, {x} from 'bar';`
   );
   const code = generateJs(path);
-  expect(code.trim()).toEqual(
-    `import foo from 'foo';\nimport bar, { x } from 'bar';`,
+  expect(code.trim()).toMatchInlineSnapshot(
+    `"import foo from 'foo';import bar, { x } from 'bar';"`
   );
   expect(vars).toEqual([{default: 'foo'}, {default: 'bar', x: 'x'}]);
 });

src/utils/generate-js.js

@@ -22,30 +22,8 @@ THE SOFTWARE.
 @flow
 */
 
-import generate from '@babel/generator';
-import prettier from 'prettier';
-import {writeFile} from './write-file.js';
+import recast from 'recast';
 
-export type GenerateJsOptions = ?{
-  formatter: ?('babel' | 'prettier'),
-  formatterOptions: ?Object,
-};
-
-export const generateJs = (path: NodePath, options: GenerateJsOptions) => {
-  const formatter = options ? options.formatter : 'babel';
-  const formatterOptions = options ? options.formatterOptions : {};
-  switch (formatter) {
-    case 'babel':
-      const generated = generate(path.parent, formatterOptions);
-      return generated.code;
-    case 'prettier':
-    default:
-      // placeholder is needed to prevent prettier from short-circuiting before the parser runs
-      return prettier.format('__placeholder__', {
-        parser() {
-          return path.node;
-        },
-        ...formatterOptions,
-      });
-  }
+export const generateJs = (path: NodePath) => {
+  return recast.print(path.parent).code;
 };

src/utils/insert-js-after.js

@@ -28,7 +28,7 @@ export const insertJsAfter = (
   path: NodePath,
   target: string,
   code: string,
-  wildcards: Array<string> = [],
+  wildcards: Array<string> = []
 ) => {
   return replaceJs(path, target, `${target}\n${code}`, wildcards);
 };

src/utils/insert-js-before.js

@@ -28,7 +28,7 @@ export const insertJsBefore = (
   path: NodePath,
   target: string,
   code: string,
-  wildcards: Array<string> = [],
+  wildcards: Array<string> = []
 ) => {
   return replaceJs(path, target, `${code}\n${target}`, wildcards);
 };

src/utils/parse-js.js

@@ -25,8 +25,7 @@ THE SOFTWARE.
 import traverse from '@babel/traverse';
 import NodePath from '@babel/traverse/lib/path';
 import {parse} from '@babel/parser';
-import {readFile} from './read-file.js';
-import generate from '@babel/generator';
+import recast from 'recast';
 
 export type ParserOptions = ?{mode: ?('typescript' | 'flow')};
 
@@ -36,32 +35,38 @@ export const parseJs = (code: string, options: ParserOptions) => {
       ? ['typescript']
       : ['flow', 'flowComments'];
 
-  const ast = parse(code, {
-    sourceType: 'unambiguous',
-    plugins: [
-      ...typeSystem,
-      'jsx',
-      'doExpressions',
-      'objectRestSpread',
-      ['decorators', {decoratorsBeforeExport: false}],
-      'classProperties',
-      'classPrivateProperties',
-      'classPrivateMethods',
-      'exportDefaultFrom',
-      'exportNamespaceFrom',
-      'asyncGenerators',
-      'functionBind',
-      'functionSent',
-      'dynamicImport',
-      'numericSeparator',
-      'optionalChaining',
-      'importMeta',
-      'bigInt',
-      'optionalCatchBinding',
-      'throwExpressions',
-      ['pipelineOperator', {proposal: 'minimal'}],
-      'nullishCoalescingOperator',
-    ],
+  const ast = recast.parse(code, {
+    parser: {
+      parse(source) {
+        return parse(source, {
+          sourceType: 'unambiguous',
+          plugins: [
+            ...typeSystem,
+            'jsx',
+            'doExpressions',
+            'objectRestSpread',
+            ['decorators', {decoratorsBeforeExport: false}],
+            'classProperties',
+            'classPrivateProperties',
+            'classPrivateMethods',
+            'exportDefaultFrom',
+            'exportNamespaceFrom',
+            'asyncGenerators',
+            'functionBind',
+            'functionSent',
+            'dynamicImport',
+            'numericSeparator',
+            'optionalChaining',
+            'importMeta',
+            'bigInt',
+            'optionalCatchBinding',
+            'throwExpressions',
+            ['pipelineOperator', {proposal: 'minimal'}],
+            'nullishCoalescingOperator',
+          ],
+        });
+      },
+    },
   });
 
   // ensure `path` has correct type to keep flow.js happy

src/utils/read-file.test.js

@@ -22,7 +22,6 @@ THE SOFTWARE.
 @flow
 */
 
-import util from 'util';
 import fse from 'fs-extra';
 import {writeFile} from './write-file.js';
 import {readFile} from './read-file.js';

src/utils/remove-js-imports.test.js

@@ -63,7 +63,7 @@ test('removeJsImports dependent statements', () => {
     c.toString();
     function x(a) {
       a();
-    }`,
+    }`
   );
   removeJsImports(path, `import a, {b} from 'c';`);
   expect(generateJs(path).trim()).toEqual('function x(a) {\n  a();\n}');
@@ -75,7 +75,7 @@ test('removeJsImports namespace dependent statements', () => {
     foo(a.test());
     function x(a) {
       a();
-    }`,
+    }`
   );
   removeJsImports(path, `import * as a from 'c';`);
   expect(generateJs(path).trim()).toEqual('function x(a) {\n  a();\n}');

src/utils/replace-js.js

@@ -29,7 +29,7 @@ export const replaceJs = (
   path: NodePath,
   source: string,
   target: string,
-  wildcards: Array<string> = [],
+  wildcards: Array<string> = []
 ): boolean => {
   const sourcePath = parseJs(source);
   const sourceNode = sourcePath.node.body[0];

src/utils/visit-js-import.js

@@ -31,21 +31,21 @@ import {
 export const visitJsImport = (
   path: NodePath,
   source: string,
-  handler: (path: NodePath, refPaths: Array<NodePath>) => Boolean | void,
+  handler: (path: NodePath, refPaths: Array<NodePath>) => Boolean | void
 ) => {
   const sourcePath = parseJs(source);
   const sourceNode = sourcePath.node.body[0];
   if (sourceNode.type !== 'ImportDeclaration') {
     throw new Error(
       `Expected source with type ImportDeclaration. Received: ${
         sourceNode.type
-      }`,
+      }`
     );
   }
   const specifiers = sourceNode.specifiers;
   if (specifiers.length !== 1) {
     throw new Error(
-      `Expected exactly one import specifier. Received: ${specifiers.length}`,
+      `Expected exactly one import specifier. Received: ${specifiers.length}`
     );
   }
   const sourceSpecifier = specifiers[0];

src/utils/visit-js-import.test.js

@@ -38,7 +38,7 @@ test('visitJsImport named', () => {
     expect(refPaths).toHaveLength(2);
   });
   visitJsImport(path, `import {a} from 'c'`, handler);
-  expect(handler).toBeCalledTimes(1);
+  expect(handler).toHaveBeenCalledTimes(1);
 });
 
 test('visitJsImport no references', () => {
@@ -49,7 +49,7 @@ test('visitJsImport no references', () => {
     expect(refPaths).toHaveLength(0);
   });
   visitJsImport(path, `import {a} from 'c'`, handler);
-  expect(handler).toBeCalledTimes(1);
+  expect(handler).toHaveBeenCalledTimes(1);
 });
 
 test('visitJsImport no binding', () => {
@@ -60,7 +60,7 @@ test('visitJsImport no binding', () => {
     expect(refPaths).toHaveLength(0);
   });
   visitJsImport(path, `import {a} from 'c'`, handler);
-  expect(handler).toBeCalledTimes(0);
+  expect(handler).toHaveBeenCalledTimes(0);
 });
 
 test('visitJsImport namespace', () => {
@@ -77,7 +77,7 @@ test('visitJsImport namespace', () => {
     expect(refPaths).toHaveLength(2);
   });
   visitJsImport(path, `import * as b from 'c'`, handler);
-  expect(handler).toBeCalledTimes(1);
+  expect(handler).toHaveBeenCalledTimes(1);
 });
 
 test('visitJsImport default', () => {
@@ -94,7 +94,7 @@ test('visitJsImport default', () => {
     expect(refPaths).toHaveLength(2);
   });
   visitJsImport(path, `import b from 'c'`, handler);
-  expect(handler).toBeCalledTimes(1);
+  expect(handler).toHaveBeenCalledTimes(1);
 });
 
 test('visitJsImport validation', () => {

src/utils/with-ignore-file.js

@@ -26,7 +26,7 @@ import {readFile} from '../utils/read-file.js';
 import {writeFile} from '../utils/write-file.js';
 
 export type IgnoreFileMutation = (
-  data: Array<string>,
+  data: Array<string>
 ) => Promise<?Array<string>>;
 
 export const withIgnoreFile = async (file: string, fn: IgnoreFileMutation) => {