feat: add npm diffruyadorno/npm-diff

- As proposed in RFC: https://github.com/npm/rfcs/pull/144

PR-URL: https://github.com/npm/cli/pull/1319
Credit: @ruyadorno
Close: #1319
Reviewed-by: @isaacs

5 files changed, 164 insertions, 0 deletions

diff --git a/node_modules/@npmcli/disparity-colors/CHANGELOG.md b/node_modules/@npmcli/disparity-colors/CHANGELOG.md
new file mode 100644
index 000000000..216d1db90
--- /dev/null
+++ b/node_modules/@npmcli/disparity-colors/CHANGELOG.md
@@ -0,0 +1,6 @@
+# Changelog
+
+## 1.0.0
+
+- Initial release
+
diff --git a/node_modules/@npmcli/disparity-colors/LICENSE b/node_modules/@npmcli/disparity-colors/LICENSE
new file mode 100644
index 000000000..dedcd7d2f
--- /dev/null
+++ b/node_modules/@npmcli/disparity-colors/LICENSE
@@ -0,0 +1,15 @@
+The ISC License
+
+Copyright (c) npm Inc.
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/node_modules/@npmcli/disparity-colors/README.md b/node_modules/@npmcli/disparity-colors/README.md
new file mode 100644
index 000000000..a89be36d8
--- /dev/null
+++ b/node_modules/@npmcli/disparity-colors/README.md
@@ -0,0 +1,49 @@
+# @npmcli/disparity-colors
+
+[![NPM version](https://img.shields.io/npm/v/@npmcli/disparity-colors)](https://www.npmjs.com/package/@npmcli/disparity-colors)
+[![Build Status](https://img.shields.io/github/workflow/status/npm/disparity-colors/node-ci)](https://github.com/npm/disparity-colors)
+[![License](https://img.shields.io/github/license/npm/disparity-colors)](https://github.com/npm/disparity-colors/blob/master/LICENSE)
+
+Spiritual sucessor to [disparity](https://www.npmjs.com/package/disparity). Colorizes [Diff Unified format](https://en.wikipedia.org/wiki/Diff#Unified_format) output using [ansi-styles](https://www.npmjs.com/package/ansi-styles).
+
+## Install
+
+`npm install @npmcli/disparity-colors`
+
+## Usage:
+
+```js
+const colorize = require('@npmcli/disparity-colors')
+mapWorkspaces(`--- a/src/index.js
++++ b/src/index.js
+@@ -1,4 +1,5 @@
+ "use strict";
++"use foo";
+
+ const os = require("os");
+`)
+// --- a/src/index.js
+// +++ b/src/index.js
+// @@ -1,4 +1,5 @@
+// "use strict";
+// +"use foo";
+// 
+// const os = require("os");
+```
+
+## API:
+
+### `colorize(str, opts = {}) -> String`
+
+- `str`: A [Diff Unified format](https://en.wikipedia.org/wiki/Diff#Unified_format) string
+- `opts`:
+  - `headerLength`: A **Number** defining how many lines should be colorized as header
+
+#### Returns
+
+A **String** including the appropriate [ANSI escape codes](https://en.wikipedia.org/wiki/ANSI_escape_code#Colors_and_Styles)
+
+## LICENSE
+
+[ISC](./LICENSE)
+
diff --git a/node_modules/@npmcli/disparity-colors/index.js b/node_modules/@npmcli/disparity-colors/index.js
new file mode 100644
index 000000000..a02b8f884
--- /dev/null
+++ b/node_modules/@npmcli/disparity-colors/index.js
@@ -0,0 +1,34 @@
+const ansi = require('ansi-styles')
+
+const colors = {
+  removed: ansi.red,
+  added: ansi.green,
+  header: ansi.yellow,
+  section: ansi.magenta
+}
+
+function colorize (str, opts) {
+  let headerLength = (opts || {}).headerLength
+  if (typeof headerLength !== 'number' || Number.isNaN(headerLength)) {
+    headerLength = 2
+  }
+
+  const color = (str, colorId) => {
+    const { open, close } = colors[colorId]
+    // avoid highlighting the "\n" (would highlight till the end of the line)
+    return str.replace(/[^\n\r]+/g, open + '$&' + close)
+  }
+
+  // this RegExp will include all the `\n` chars into the lines, easier to join
+  const lines = ((typeof str === 'string' && str) || '').split(/^/m)
+
+  const start = color(lines.slice(0, headerLength).join(''), 'header')
+  const end = lines.slice(headerLength).join('')
+    .replace(/^-.*/gm, color('$&', 'removed'))
+    .replace(/^\+.*/gm, color('$&', 'added'))
+    .replace(/^@@.+@@/gm, color('$&', 'section'))
+
+  return start + end
+}
+
+module.exports = colorize
diff --git a/node_modules/@npmcli/disparity-colors/package.json b/node_modules/@npmcli/disparity-colors/package.json
new file mode 100644
index 000000000..3f389a42c
--- /dev/null
+++ b/node_modules/@npmcli/disparity-colors/package.json
@@ -0,0 +1,60 @@
+{
+  "name": "@npmcli/disparity-colors",
+  "version": "1.0.1",
+  "files": [
+    "index.js"
+  ],
+  "engines": {
+    "node": ">=10"
+  },
+  "description": "Colorizes unified diff output",
+  "repository": "https://github.com/npm/disparity-colors",
+  "keywords": [
+    "disparity",
+    "npm",
+    "npmcli",
+    "diff",
+    "char",
+    "unified",
+    "multiline",
+    "string",
+    "color",
+    "ansi",
+    "terminal",
+    "cli",
+    "tty"
+  ],
+  "author": "npm Inc. <support@npmjs.com>",
+  "contributors": [
+    {
+      "name": "Ruy Adorno",
+      "url": "https://ruyadorno.com",
+      "twitter": "ruyadorno"
+    }
+  ],
+  "license": "ISC",
+  "scripts": {
+    "lint": "standard index.js",
+    "pretest": "npm run lint",
+    "test": "tap",
+    "snap": "tap",
+    "preversion": "npm test",
+    "postversion": "npm publish",
+    "prepublishOnly": "git push origin --follow-tags"
+  },
+  "tap": {
+    "check-coverage": true
+  },
+  "standard": {
+    "ignore": [
+      "/tap-snapshots/"
+    ]
+  },
+  "devDependencies": {
+    "standard": "^16.0.3",
+    "tap": "^14.11.0"
+  },
+  "dependencies": {
+    "ansi-styles": "^4.3.0"
+  }
+}