Fix regression for entirely missing package

pgonzal · pgonzal · commit 4114de473d5f · 2018-04-11T17:40:13.000-07:00
diff --git a/common/scripts/InstallRushOnlyIfNeeded.js b/common/scripts/InstallRushOnlyIfNeeded.js
@@ -83,14 +83,23 @@ if (fs.existsSync(npmrcPath)) {
 
 // Check for the Rush version
 let installedVersion = undefined;
+let installedVersionValid = false
 console.log(os.EOL + `Expected Rush version is ${expectedVersion}`);
 
 try {
   const spawnResult = child_process.spawnSync(npmPath, ['list', packageName, 'version'],
     { cwd: rushPath, stdio: ['pipe', 'pipe', 'pipe'] });
+  const output = spawnResult.output.toString();
   const matches = /@microsoft\/rush\@([0-9a-zA-Z.+\-]+)/.exec(spawnResult.output);
-  if (matches && matches.length === 2) {
+  // If NPM finds the wrong version in node_modules, that version will be in matches[1].
+  // But if it's not installed at all, then NPM instead uselessly tells us all about
+  // the version that we DON'T have ("missing:")
+  if (matches && matches.length === 2 && !output.match(/missing\:/g)) {
     installedVersion = matches[1];
+
+    if (spawnResult.status === 0) {
+      installedVersionValid = true
+    }
   }
 }
 catch (error) {
@@ -103,7 +112,7 @@ if (installedVersion) {
   console.log(os.EOL + 'Rush does not appear to be installed');
 }
 
-if (installedVersion !== expectedVersion) {
+if (!installedVersionValid || installedVersion !== expectedVersion) {
   console.log(os.EOL + 'Installing Rush...');
   child_process.execSync(`"${npmPath}" install ${packageName}@${expectedVersion}`, { cwd: rushPath });
   console.log(os.EOL + `Successfully installed Rush ${expectedVersion}`);
