feat: add create functionality

README.md

@@ -58,36 +58,48 @@ Creates a new empty instance of `PackageJson`.
 
 ---
 
-### `async PackageJson.load(path)`
+### `async PackageJson.create(path)`
 
-Loads the `package.json` at the given path.
+Creates an empty `package.json` at the given path. If one already exists
+it will be overwritten.
+
+---
+
+### `async PackageJson.load(path, opts = {})`
+
+Loads a `package.json` at the given path.
+
+- `opts`: `Object` can contain:
+  - `create`: `Boolean` if true, a new package.json will be created if
+      one does not already exist. Will not clobber ane existing
+      package.json that can not be parsed.
 
 ### Example:
 
-Loads contents of the `package.json` file located at `./`:
+Loads contents of a `package.json` file located at `./`:
 
 ```js
 const PackageJson = require('@npmcli/package-json')
 const pkgJson = new PackageJson()
 await pkgJson.load('./')
 ```
 
-Throws an error in case the `package.json` file is missing or has invalid
+Throws an error in case a `package.json` file is missing or has invalid
 contents.
 
 ---
 
 ### **static** `async PackageJson.load(path)`
 
 Convenience static method that returns a new instance and loads the contents of
-the `package.json` file from that location.
+a `package.json` file from that location.
 
 - `path`: `String` that points to the folder from where to read the
 `package.json` from
 
 ### Example:
 
-Loads contents of the `package.json` file located at `./`:
+Loads contents of a `package.json` file located at `./`:
 
 ```js
 const PackageJson = require('@npmcli/package-json')
@@ -124,7 +136,7 @@ Convenience static that calls `load` before calling `prepare`
 
 ### `PackageJson.update(content)`
 
-Updates the contents of the `package.json` with the `content` provided.
+Updates the contents of a `package.json` with the `content` provided.
 
 - `content`: `Object` containing the properties to be updated/replaced in the
 `package.json` file.

lib/index.js

@@ -52,10 +52,33 @@ class PackageJson {
     'binRefs',
   ])
 
-  // default behavior, loads a package.json at given path and JSON parses
-  static async load (path) {
+  // create a new empty package.json, so we can save at the given path even
+  // though we didn't start from a parsed file
+  static async create (path, opts = {}) {
     const p = new PackageJson()
-    return p.load(path)
+    await p.create(path)
+    if (opts.data) {
+      return p.update(opts.data)
+    }
+    return p
+  }
+
+  // Loads a package.json at given path and JSON parses
+  static async load (path, opts = {}) {
+    const p = new PackageJson()
+    // Avoid try/catch if we aren't going to create
+    if (!opts.create) {
+      return p.load(path)
+    }
+
+    try {
+      return await p.load(path)
+    } catch (err) {
+      if (!err.message.startsWith('Could not read package.json')) {
+        throw err
+      }
+      return await p.create(path)
+    }
   }
 
   // read-package-json compatible behavior
@@ -159,10 +182,18 @@ class PackageJson {
     return undefined
   }
 
+  create (path) {
+    this.#path = path
+    this.#manifest = {}
+    return this
+  }
+
+  // This should be the ONLY way to set content in the manifest
   update (content) {
     if (!this.content) {
-      throw new Error('Can not update without existing data')
+      throw new Error('Can not update without content.  Please `load` or `create`')
     }
+
     for (const step of knownSteps) {
       this.#manifest = step({ content, originalContent: this.content })
     }
@@ -186,11 +217,8 @@ class PackageJson {
       [Symbol.for('newline')]: newline,
     } = this.content
 
-    // These can only be undefined if we didn't parse JSON, which we currently don't support.
-    // const format = indent === undefined ? '  ' : indent
-    // const eol = newline === undefined ? '\n' : newline
-    const format = indent
-    const eol = newline
+    const format = indent === undefined ? '  ' : indent
+    const eol = newline === undefined ? '\n' : newline
     const fileContent = `${
       JSON.stringify(this.content, null, format)
     }\n`

lib/normalize.js

@@ -8,7 +8,7 @@ const git = require('@npmcli/git')
 
 const normalize = async (pkg, { strict, steps, root }) => {
   if (!pkg.content) {
-    throw new Error('Can not normalize without existing data')
+    throw new Error('Can not normalize without content')
   }
   const data = pkg.content
   const scripts = data.scripts || {}

tap-snapshots/test/index.js.test.cjs

@@ -5,31 +5,41 @@
  * Make sure to inspect the output below.  Do not ignore changes!
  */
 'use strict'
-exports[`test/index.js TAP custom formatting > should save back custom format to package.json 1`] = `
-{"name":"foo","version":"1.0.1","description":"Lorem ipsum dolor"}
+exports[`test/index.js TAP create with data > should save package.json with name 1`] = `
+{
+  "name": "create-test"
+}
+
 `
 
-exports[`test/index.js TAP invalid package.json data > should save updated content to package.json and ignore invalid data 1`] = `
-this! is! not! json!
+exports[`test/index.js TAP create without data > should save empty package.json 1`] = `
+{}
+
 `
 
-exports[`test/index.js TAP read, update content and write > should properly save contennt to a package.json 1`] = `
-{
-        "name": "foo",
-        "version": "1.0.1",
-        "description": "Lorem ipsum dolor"
-}
+exports[`test/index.js TAP load create:true empty dir > should save empty package.json 1`] = `
+{}
+
+`
 
+exports[`test/index.js TAP load create:true existing parseable package.json > package.json should match existing 1`] = `
+{"name":"test-package"}
 `
 
-exports[`test/index.js TAP start new package.json, update and write > should properly save contentn to a package.json 1`] = `
+exports[`test/index.js TAP load custom formatting > should save back custom format to package.json 1`] = `
+{"name":"foo","version":"1.0.1","description":"Lorem ipsum dolor"}
+`
+
+exports[`test/index.js TAP load read, update content and write > should properly save contennt to a package.json 1`] = `
 {
-  "name": "foo"
+        "name": "foo",
+        "version": "1.0.1",
+        "description": "Lorem ipsum dolor"
 }
 
 `
 
-exports[`test/index.js TAP update long package.json > should only update the defined property 1`] = `
+exports[`test/index.js TAP load update long package.json > should only update the defined property 1`] = `
 {
   "version": "7.18.1",
   "name": "npm",
@@ -274,7 +284,7 @@ exports[`test/index.js TAP update long package.json > should only update the def
 
 `
 
-exports[`test/index.js TAP update long package.json > should properly write updated pacakge.json contents 1`] = `
+exports[`test/index.js TAP load update long package.json > should properly write updated pacakge.json contents 1`] = `
 {
   "version": "7.18.1",
   "name": "npm",