Make elm a peer dependency.

Author: Elbek Azimov

appveyor.yml

@@ -1,4 +1,4 @@
-image: Visual Studio 2017
+image: Visual Studio 2019
 
 platform:
   - x64
@@ -23,8 +23,13 @@ skip_commits:
     - '**/*.md'
 
 test_script:
-  - node --version
-  - npm --version
-  - npm install
-  - npm link
-  - npm run test
+  - ps: node --version
+  - ps: npm --version
+  - ps: npm config set loglevel silent
+  # NPM prefix should be writable by current user.
+  - ps: npm config set prefix "$home\\.npm-prefix"
+  - ps: $env:Path += ";$home\\.npm-prefix\\"
+  - ps: npm install -g 'elm@^0.19.1' 'elm-test@^0.19.1'
+  - ps: npm install
+  - ps: npm link
+  - ps: npm run test

bin/create-elm-app-cli.js

@@ -6,7 +6,9 @@ const path = require('path');
 const spawn = require('cross-spawn');
 const argv = require('minimist')(process.argv.slice(2));
 const version = require('../package.json').version;
-const elmVersion = require('elm/package.json').version;
+const which = require('which');
+const elmExecutable = which.sync('elm', {nothrow: true}) || require.resolve('elm/bin/elm');
+const elmVersion = spawn.sync(elmExecutable, ['--version']).stdout.toString().trim();
 const commands = argv._;
 
 if (commands.length === 0) {

bin/elm-app-cli.js

@@ -5,9 +5,11 @@
 const path = require('path');
 const spawn = require('cross-spawn');
 const argv = require('minimist')(process.argv.slice(2));
-const elmExecutable = require.resolve('elm/bin/elm');
+const which = require('which');
+const elmExecutable = which.sync('elm', {nothrow: true}) || require.resolve('elm/bin/elm');
+const elmTestExecutable = which.sync('elm-test', {nothrow: true}) || require.resolve('elm-test/bin/elm-test');
 const version = require('../package.json').version;
-const elmVersion = require('elm/package.json').version;
+const elmVersion = spawn.sync(elmExecutable, ['--version']).stdout.toString().trim();
 
 const commands = argv._;
 
@@ -66,8 +68,8 @@ switch (script) {
       }
     });
 
-    args = args.concat(['--compiler', require.resolve('elm/bin/elm')]);
-    const cp = spawn.sync(require.resolve('elm-test/bin/elm-test'), args, {
+    args = args.concat(['--compiler', elmExecutable]);
+    const cp = spawn.sync(elmTestExecutable, args, {
       stdio: 'inherit'
     });
 

config/paths.js

@@ -4,6 +4,7 @@ const path = require('path');
 const fs = require('fs');
 const url = require('url');
 const cosmiconfig = require('cosmiconfig');
+const which = require('which');
 
 // Make sure any symlinks in the project folder are resolved:
 // https://github.com/facebookincubator/create-react-app/issues/637
@@ -76,7 +77,7 @@ module.exports = {
   entry: resolveApp('./src/index.js'),
   appBuild: resolveApp('./build'),
   elmJson: resolveApp('./elm.json'),
-  elm: require.resolve('elm/bin/elm'),
+  elm: which.sync('elm', {nothrow: true}) || require.resolve('elm/bin/elm'),
   publicUrl: getPublicUrl(config),
   servedPath: getServedPath(config),
   proxy: config.proxy,

package.json

@@ -35,10 +35,8 @@
     "cross-spawn": "7.0.3",
     "css-loader": "4.3.0",
     "dotenv": "8.2.0",
-    "elm": "latest-0.19.1",
     "elm-asset-webpack-loader": "1.1.2",
     "elm-hot-webpack-loader": "1.1.7",
-    "elm-test": "latest-0.19.1",
     "elm-webpack-loader": "6.0.1",
     "file-loader": "6.2.0",
     "fs-extra": "6.0.1",
@@ -65,6 +63,7 @@
     "webpack-dev-server": "3.11.0",
     "webpack-manifest-plugin": "2.2.0",
     "whatwg-fetch": "3.5.0",
+    "which": "^2.0.2",
     "workbox-webpack-plugin": "4.3.1"
   },
   "devDependencies": {
@@ -87,6 +86,10 @@
     "shelljs": "0.8.3",
     "unexpected": "12.0.0"
   },
+  "peerDependencies": {
+    "elm": "latest-0.19.1",
+    "elm-test": "latest-0.19.1"
+  },
   "engines": {
     "node": ">=8.0.0"
   },

scripts/create.js

@@ -7,6 +7,8 @@ const chalk = require('chalk');
 const spawn = require('cross-spawn');
 const argv = require('minimist')(process.argv.slice(2));
 const commands = argv._;
+const which = require('which');
+const elmExecutable = which.sync('elm', {nothrow: true}) || require.resolve('elm/bin/elm');
 
 const isWindows = process.platform === 'win32';
 
@@ -44,7 +46,7 @@ function createElmApp(name) {
 
   // Run initial `elm make`
   const spawnElmPkgResult = spawn.sync(
-    path.resolve(__dirname, '../node_modules/.bin/elm'),
+    elmExecutable,
     // Run elm-make to install the dependencies.
     ['make', 'src/Main.elm', '--output=/dev/null'],
     { stdio: 'inherit', cwd: appRoot }