feat: add support for package.json5 format

Author: kokoichi206

README.md

@@ -44,7 +44,7 @@ If `run_install` is a YAML string representation of either an object or an array
 
 ### `package_json_file`
 
-**Optional** (_type:_ `string`, _default:_ `package.json`) File path to the `package.json`/[`package.yaml`](https://github.com/pnpm/pnpm/pull/1799) to read "packageManager" configuration.
+**Optional** (_type:_ `string`, _default:_ `package.json`) File path to the `package.json`/[`package.yaml`](https://github.com/pnpm/pnpm/pull/1799)/`package.json5` to read "packageManager" configuration.
 
 ### `standalone`
 

dist/index.js

@@ -12,6 +12,7 @@
     "@types/node": "^20.11.5",
     "@types/node-fetch": "^2.6.11",
     "expand-tilde": "^2.0.2",
+    "json5": "^2.2.3",
     "yaml": "^2.3.4",
     "zod": "^3.22.4"
   },

package.json

@@ -7,6 +7,7 @@ import { execPath } from 'process'
 import util from 'util'
 import { Inputs } from '../inputs'
 import YAML from 'yaml'
+import JSON5 from 'json5'
 
 export async function runSelfInstaller(inputs: Inputs): Promise<number> {
   const { version, dest, packageJsonFile, standalone } = inputs
@@ -64,7 +65,7 @@ async function readTarget(opts: {
       const content = readFileSync(path.join(GITHUB_WORKSPACE, packageJsonFile), 'utf8');
       ({ packageManager } = packageJsonFile.endsWith(".yaml")
         ? YAML.parse(content, { merge: true })
-        : JSON.parse(content)
+        : JSON5.parse(content)
       )
     } catch (error: unknown) {
       // Swallow error if package.json doesn't exist in root