feat: import-attributes support

.eslintignore

@@ -2,4 +2,7 @@ node_modules/*
 local/*
 vendor/*
 dist/*
-src/tests/fixtures/deprecated/es5.js
+src/tests/fixtures/deprecated/es5.js
+src/tests/fixtures/syntax/import.js
+src/tests/fixtures/syntax/export.js
+src/tests/fixtures/tree/es6.js

package.json

@@ -53,6 +53,7 @@
     "@babel/parser": "^7.16.4",
     "@babel/preset-env": "^7.14.4",
     "acorn": "^8.6.0",
+    "acorn-import-attributes": "^1.9.5",
     "astravel": "^0.5.0",
     "ava": "^3.15.0",
     "babel-preset-minify": "^0.5.1",

src/astring.js

@@ -538,7 +538,7 @@ export const GENERATOR = {
   },
   ImportDeclaration(node, state) {
     state.write('import ')
-    const { specifiers } = node
+    const { specifiers, attributes } = node
     const { length } = specifiers
     // TODO: Once babili is fixed, put this after condition
     // https://github.com/babel/babili/issues/430
@@ -583,8 +583,23 @@ export const GENERATOR = {
       state.write(' from ')
     }
     this.Literal(node.source, state)
+
+    if (attributes && attributes.length > 0) {
+      state.write(' with { ')
+      for (let i = 0; i < attributes.length; i++) {
+        this.ImportAttribute(attributes[i], state)
+        if (i < attributes.length - 1) state.write(', ')
+      }
+
+      state.write(' }')
+    }
     state.write(';')
   },
+  ImportAttribute(node, state) {
+    this.Identifier(node.key, state)
+    state.write(': ')
+    this.Literal(node.value, state)
+  },
   ImportExpression(node, state) {
     state.write('import(')
     this[node.source.type](node.source, state)
@@ -629,6 +644,17 @@ export const GENERATOR = {
         state.write(' from ')
         this.Literal(node.source, state)
       }
+
+      if (node.attributes && node.attributes.length > 0) {
+        state.write(' with { ')
+        for (let i = 0; i < node.attributes.length; i++) {
+          this.ImportAttribute(node.attributes[i], state)
+          if (i < node.attributes.length - 1) state.write(', ')
+        }
+
+        state.write(' }')
+      }
+
       state.write(';')
     }
   },
@@ -639,6 +665,17 @@ export const GENERATOR = {
       state.write('export * from ')
     }
     this.Literal(node.source, state)
+
+    if (node.attributes && node.attributes.length > 0) {
+      state.write(' with { ')
+      for (let i = 0; i < node.attributes.length; i++) {
+        this.ImportAttribute(node.attributes[i], state)
+        if (i < node.attributes.length - 1) state.write(', ')
+      }
+
+      state.write(' }')
+    }
+
     state.write(';')
   },
   MethodDefinition(node, state) {

src/tests/astring.js

@@ -1,7 +1,8 @@
 import fs from 'fs'
 import test from 'ava'
 import path from 'path'
-import { parse } from 'acorn'
+import { Parser } from 'acorn'
+import { importAttributesOrAssertions } from 'acorn-import-attributes'
 import * as astravel from 'astravel'
 import { pick } from 'lodash'
 
@@ -12,6 +13,8 @@ const FIXTURES_FOLDER = path.join(__dirname, 'fixtures')
 
 const ecmaVersion = 13
 
+const parser = Parser.extend(importAttributesOrAssertions)
+
 const stripLocation = astravel.makeTraveler({
   go(node, state) {
     delete node.start
@@ -27,6 +30,23 @@ const stripLocation = astravel.makeTraveler({
     // Always walk through value, regardless of `node.shorthand` flag
     this.go(node.value, state)
   },
+  // astravel does not support import attributes yet
+  ImportDeclaration(node, state) {
+    const { specifiers } = node,
+      { length } = specifiers
+    for (let i = 0; i < length; i++) {
+      this.go(specifiers[i], state)
+    }
+    const { attributes } = node
+    if (attributes != null)
+      for (let i = 0; i < attributes.length; i++) this.go(attributes[i], state)
+
+    this.go(node.source, state)
+  },
+  ImportAttribute(node, state) {
+    this.go(node.key, state)
+    this.go(node.value, state)
+  },
 })
 
 test('Syntax check', (assert) => {
@@ -38,7 +58,7 @@ test('Syntax check', (assert) => {
   }
   files.forEach((filename) => {
     const code = readFile(path.join(dirname, filename))
-    const ast = parse(code, options)
+    const ast = parser.parse(code, options)
     assert.is(
       generate(ast),
       code,
@@ -57,9 +77,9 @@ test('Tree comparison', (assert) => {
   }
   files.forEach((filename) => {
     const code = readFile(path.join(dirname, filename))
-    const ast = parse(code, options)
+    const ast = parser.parse(code, options)
     stripLocation.go(ast)
-    const formattedAst = parse(generate(ast), options)
+    const formattedAst = parser.parse(generate(ast), options)
     stripLocation.go(formattedAst)
     assert.deepEqual(
       formattedAst,
@@ -76,7 +96,7 @@ test('Deprecated syntax check', (assert) => {
   files.forEach((filename) => {
     const code = readFile(path.join(dirname, filename))
     const version = parseInt(filename.substring(2, filename.length - 3))
-    const ast = parse(code, { ecmaVersion: version })
+    const ast = parser.parse(code, { ecmaVersion: version })
     assert.is(generate(ast), code, 'es' + version)
   })
 })
@@ -89,7 +109,7 @@ test('Output stream', (assert) => {
       this.buffer += code
     },
   }
-  const ast = parse(code, {
+  const ast = parser.parse(code, {
     ecmaVersion,
   })
   const result = generate(ast, {
@@ -108,7 +128,7 @@ test('Comment generation', (assert) => {
   files.forEach((filename) => {
     const code = readFile(path.join(dirname, filename))
     const comments = []
-    const ast = parse(code, {
+    const ast = parser.parse(code, {
       ecmaVersion,
       locations: true,
       onComment: comments,
@@ -150,7 +170,7 @@ test('Source map generation', (assert) => {
         })
       },
     }
-    const ast = parse(code, options)
+    const ast = parser.parse(code, options)
     generate(ast, {
       sourceMap,
     })
@@ -185,7 +205,7 @@ test('Source map generation with comments', (assert) => {
       },
     }
     const comments = []
-    const ast = parse(code, {
+    const ast = parser.parse(code, {
       ecmaVersion,
       comments: true,
       locations: true,

src/tests/fixtures/other/a.json

@@ -0,0 +1,3 @@
+{
+    "content": "For testing import-attributes"
+}

src/tests/fixtures/syntax/export.js

@@ -9,3 +9,4 @@ export default i = 42;
 export var j = 42;
 export let k = 42;
 export function l() {}
+export {val} from '../other/a.json' with { type: "json" };

src/tests/fixtures/syntax/import.js

@@ -4,5 +4,7 @@ import * as d from "module";
 import e, {f as g, h as i, j} from "module";
 import {k as l, m} from "module";
 import {n, o as p} from "module";
+import * as q from "../other/a.json" with { type: "json" };
+import r from "../other/a.json" with { type: "json" };
 import("module");
 const x = import("module");

src/tests/fixtures/tree/es6.js

@@ -42,6 +42,8 @@ import i4, * as i5 from "module";
 import i6, {} from "module";
 import i7, { i8, var as i9 } from "module";
 import "module";
+import * as q from "./a.json" with { type: "json" };
+import r from "./a.json" with { type: "json" };
 
 export * from "module";
 export {} from "module";

src/tests/scripts.js

@@ -2,7 +2,8 @@ import test from 'ava'
 import fs from 'fs'
 import path from 'path'
 import normalizeNewline from 'normalize-newline'
-import { parse } from 'acorn'
+import { Parser } from 'acorn'
+import { importAttributes } from 'acorn-import-attributes'
 import * as astravel from 'astravel'
 import glob from 'glob'
 
@@ -40,12 +41,15 @@ test('Script tests', (assert) => {
       const code = normalizeNewline(fs.readFileSync(fileName, 'utf8'))
       let ast
       try {
-        ast = parse(code, options)
+        ast = Parser.extend(importAttributes).parse(code, options)
       } catch (error) {
         return
       }
       stripLocation.go(ast)
-      const formattedAst = parse(generate(ast), options)
+      const formattedAst = Parser.extend(importAttributes).parse(
+        generate(ast),
+        options,
+      )
       stripLocation.go(formattedAst)
       assert.deepEqual(formattedAst, ast, fileName)
     } catch (error) {