build: install nyc on demand

.travis.yml

@@ -56,8 +56,7 @@ before_install:
   - "npm config set shrinkwrap false"
 
   # Setup Node.js version-specific dependencies
-  - "test $TRAVIS_NODE_VERSION != '0.6' || npm rm --save-dev nyc"
-  - "test $TRAVIS_NODE_VERSION != '0.8' || npm rm --save-dev nyc"
+  - "node tool/install-nyc.js --nyc-optional"
   - "test $(echo $TRAVIS_NODE_VERSION | cut -d. -f1) -ge 4 || npm rm --save-dev eslint"
 
   # Update Node.js modules
@@ -78,10 +77,9 @@ before_script:
   - "docker exec mysql mysql -e 'select version()'"
 
 script:
-  # Run test script, depending on nyc install
-  - "test ! -z $(npm -ps ls nyc) || npm test"
-  - "test   -z $(npm -ps ls nyc) || npm run-script test-ci"
-  - "test   -z $(npm -ps ls eslint) || npm run-script lint"
+  # Run test script
+  - "npm run-script test-ci"
+  - "test -z $(npm -ps ls eslint) || npm run-script lint"
 
 after_script:
   - "test -d .nyc_output && npm install coveralls@2 && nyc report --reporter=text-lcov | coveralls"

appveyor.yml

@@ -32,7 +32,7 @@ install:
       catch { Update-NodeJsInstallation (Get-NodeJsLatestBuild $env:nodejs_version) }
   - npm config set shrinkwrap false
   - if "%nodejs_version%" equ "0.8" npm config set strict-ssl false
-  - npm rm --silent --save-dev eslint nyc
+  - npm rm --silent --save-dev eslint
   - if exist node_modules npm prune
   - if exist node_modules npm rebuild
   - npm install

package.json

@@ -21,7 +21,6 @@
   "devDependencies": {
     "after": "0.8.2",
     "eslint": "4.19.1",
-    "nyc": "10.3.2",
     "seedrandom": "2.4.4",
     "timezone-mock": "0.0.7",
     "urun": "0.0.8",
@@ -40,8 +39,8 @@
   "scripts": {
     "lint": "eslint .",
     "test": "node test/run.js",
-    "test-ci": "nyc --reporter=text npm test",
-    "test-cov": "nyc --reporter=html --reporter=text npm test",
+    "test-ci": "node tool/install-nyc.js --nyc-optional --reporter=text -- npm test",
+    "test-cov": "node tool/install-nyc.js --reporter=html --reporter=text -- npm test",
     "version": "node tool/version-changes.js && git add Changes.md"
   }
 }

tool/install-nyc.js

@@ -0,0 +1,96 @@
+var path  = require('path');
+var spawn = require('child_process').spawn;
+
+process.nextTick(run);
+
+function installNpmModule(name, version, callback) {
+  if (getPackageVersion(name) === version) {
+    callback();
+    return;
+  }
+
+  var spec  = name + '@' + version;
+  var args  = ['install', '--silent', '--no-save', spec];
+  var child = spawn('npm', args, {
+    cwd   : path.join(__dirname, '..'),
+    shell : true
+  });
+
+  child.stderr.resume();
+  child.stdout.resume();
+
+  child.on('exit', function (code) {
+    var err = null;
+
+    if (code !== 0) {
+      err = new Error('npm install ' + spec + ' failed with exit code ' + code);
+    }
+
+    callback(err);
+  });
+}
+
+function getNycVersion() {
+  var nodeVersion = process.version.replace(/^v/, '').split('.')
+    .map(function (s) { return Number(s); });
+
+  if (nodeVersion[0] === 0 && nodeVersion[1] < 10) {
+    return undefined;
+  } else if (nodeVersion[0] < 4) {
+    return '10.3.2';
+  } else if (nodeVersion[0] < 6) {
+    return '11.9.0';
+  } else {
+    return '13.1.0';
+  }
+}
+
+function getPackageVersion(name) {
+  try {
+    return require(name + '/package').version;
+  } catch (e) {
+    return undefined;
+  }
+}
+
+function run() {
+  var args    = process.argv.slice(2);
+  var cmd     = null;
+  var divider = args.indexOf('--');
+  var version = getNycVersion();
+
+  if (divider !== -1) {
+    cmd  = args.slice(divider + 1);
+    args = args.slice(0, divider);
+  }
+
+  if (!version && args.indexOf('--nyc-optional') === -1) {
+    console.error('nyc does not support current Node.js version');
+    process.exit(1);
+  } else if (version) {
+    installNpmModule('nyc', version, function (err) {
+      if (err) {
+        console.error(err.message);
+        process.exit(1);
+      } else if (cmd) {
+        runCmd('nyc', args.concat(cmd));
+      }
+    });
+  } else if (cmd) {
+    runCmd(cmd[0], cmd.slice(1));
+  }
+}
+
+function runCmd(cmd, args) {
+  var child = spawn(cmd, args, {
+    cwd   : path.join(__dirname, '..'),
+    shell : true
+  });
+
+  child.stderr.pipe(process.stderr, {end: false});
+  child.stdout.pipe(process.stdout, {end: false});
+
+  child.on('exit', function (code) {
+    process.exit(code);
+  });
+}