feat: support comments in JSON

package.json

@@ -52,6 +52,7 @@
     "eslint-plugin-prettier": "^3.1.4",
     "execa": "^4.0.3",
     "inquirer": "^7.3.3",
+    "json5": "^2.1.3",
     "meow": "^7.1.1",
     "ncp": "^2.0.0",
     "prettier": "^2.1.2",
@@ -65,6 +66,7 @@
     "@types/eslint": "^7.2.3",
     "@types/fs-extra": "^9.0.1",
     "@types/inquirer": "^7.3.1",
+    "@types/json5": "0.0.30",
     "@types/mocha": "^8.0.3",
     "@types/ncp": "^2.0.4",
     "@types/node": "^14.11.2",

src/util.ts

@@ -20,6 +20,7 @@ import * as rimraf from 'rimraf';
 import {promisify} from 'util';
 import * as ncp from 'ncp';
 import * as writeFileAtomic from 'write-file-atomic';
+import * as JSON5 from 'json5';
 
 export const readFilep = promisify(fs.readFile);
 export const rimrafp = promisify(rimraf);
@@ -38,7 +39,7 @@ export interface DefaultPackage extends Bag<string> {
 
 export async function readJsonp(jsonPath: string) {
   const contents = await readFilep(jsonPath, {encoding: 'utf8'});
-  return JSON.parse(contents);
+  return JSON5.parse(contents);
 }
 
 export interface ReadFileP {
@@ -76,7 +77,14 @@ async function getBase(
   readFiles.add(filePath);
   try {
     const json = await customReadFilep(filePath, 'utf8');
-    let contents = JSON.parse(json);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    let contents: any;
+    try {
+      contents = JSON5.parse(json);
+    } catch (e) {
+      e.message = `Unable to parse ${filePath}!\n${e.message}`;
+      throw e;
+    }
 
     if (contents.extends) {
       const nextFile = await getBase(
@@ -85,7 +93,6 @@ async function getBase(
         readFiles,
         path.dirname(filePath)
       );
-      // eslint-disable-next-line @typescript-eslint/no-use-before-define
       contents = combineTSConfig(nextFile, contents);
     }
 

test/test-clean.ts

@@ -49,6 +49,24 @@ describe('clean', () => {
     });
   });
 
+  it('should gracefully handle JSON with comments', () => {
+    const invalidJson = `
+    {
+      // hah, comments in JSON, what a world
+      compilerOptions: {outDir: '.'}
+    }`;
+    return withFixtures({'tsconfig.json': invalidJson}, async () => {
+      await clean(OPTIONS);
+    });
+  });
+
+  it('should gracefully error if tsconfig has invalid JSON', () => {
+    const invalidJson = "silly bear, this isn't JSON!";
+    return withFixtures({'tsconfig.json': invalidJson}, async () => {
+      assert.rejects(clean(OPTIONS), /Unable to parse/);
+    });
+  });
+
   it('should avoid deleting .', () => {
     return withFixtures(
       {'tsconfig.json': JSON.stringify({compilerOptions: {outDir: '.'}})},