feat(global): add --global flag for global installation

README.md

@@ -8,6 +8,11 @@
 
 To start using it right away:
 
+```
+$ npx npm-merge-driver install --global
+```
+
+**Or** install it locally, per-project:
 ```
 $ cd /path/to/git/repository
 $ npx npm-merge-driver install

index.js

@@ -3,6 +3,7 @@
 
 const cp = require('child_process')
 const fs = require('fs')
+const mkdirp = require('mkdirp')
 const path = require('path')
 const yargs = require('yargs')
 
@@ -16,6 +17,11 @@ function parseArgs () {
       'install',
       'Set up the merge driver in the current git repository.',
     {
+      global: {
+        type: 'boolean',
+        default: false,
+        description: 'install to your user-level git configuration'
+      },
       driver: {
         type: 'string',
         default: 'npx npm-merge-driver merge %A %O %B %P',
@@ -58,17 +64,41 @@ function parseArgs () {
 }
 
 function configureGit (argv) {
+  let attrFile
+  let opts = ''
+  if (argv.global) {
+    opts = '--global'
+    try {
+      attrFile = cp
+        .execSync(`git config --global core.attributesfile`)
+        .toString('utf8')
+        .trim()
+    } catch (e) {}
+    if (!attrFile) {
+      if (process.env.XDG_CONFIG_HOME) {
+        attrFile = path.join(process.env.XDG_CONFIG_HOME, 'git', 'attributes')
+      } else {
+        attrFile = path.join(process.env.HOME, '.config', 'git', 'attributes')
+      }
+    }
+  } else {
+    opts = '--local'
+    const gitDir = cp
+      .execSync(`git rev-parse --git-dir`, {
+        encoding: 'utf8'
+      })
+      .trim()
+    attrFile = path.join(gitDir, 'info', 'attributes')
+  }
+  cp.execSync(
+    `git config ${opts} merge."${argv.driverName}".name "automatically merge npm lockfiles"`
+  )
   cp.execSync(
-    `git config merge."${argv.driverName}".name "automatically merge npm lockfiles"`
+    `git config ${opts} merge."${argv.driverName}".driver "${argv.driver}"`
   )
-  cp.execSync(`git config merge."${argv.driverName}".driver "${argv.driver}"`)
-  const gitDir = cp
-    .execSync(`git rev-parse --git-dir`, {
-      encoding: 'utf8'
-    })
-    .trim()
+  mkdirp.sync(path.dirname(attrFile))
   fs.appendFileSync(
-    path.join(gitDir, 'info', 'attributes'),
+    attrFile,
     '\n' + argv.files.map(f => `${f} merge=${argv.driverName}`).join('\n')
   )
 }

package.json

@@ -42,6 +42,7 @@
   },
   "license": "ISC",
   "dependencies": {
+    "mkdirp": "^0.5.1",
     "yargs": "^10.0.3"
   },
   "devDependencies": {
@@ -71,6 +72,7 @@
     ]
   },
   "bundleDependencies": [
-    "yargs"
+    "yargs",
+    "mkdirp"
   ]
 }