fix: don't attempt to run validate scripts if there are none to be run

Author: jrolfs

src/scripts/__tests__/__snapshots__/validate.js.snap

@@ -13,3 +13,5 @@ exports[`validate does not include "lint" if it doesn't have that script 1`] = `
 exports[`validate does not include "test" if it doesn't have that script 1`] = `concurrently --kill-others-on-fail --prefix [{name}] --names build,lint,flow --prefix-colors bgBlue.bold.reset,bgGreen.bold.reset,bgMagenta.bold.reset "yarn run build" "yarn run lint" "yarn run flow"`;
 
 exports[`validate doesn't use test or lint if it's in pre-commit 1`] = `concurrently --kill-others-on-fail --prefix [{name}] --names build,flow --prefix-colors bgBlue.bold.reset,bgGreen.bold.reset "yarn run build" "yarn run flow"`;
+
+exports[`validate exits if there are no scripts to be run 1`] = ``;

src/scripts/__tests__/validate.js

@@ -16,9 +16,8 @@ cases(
     try {
       // tests
       require('../validate')
-      expect(crossSpawnSyncMock).toHaveBeenCalledTimes(1)
-      const [firstCall] = crossSpawnSyncMock.mock.calls
-      const [script, calledArgs] = firstCall
+      const [crossSpawnFirstCall] = crossSpawnSyncMock.mock.calls
+      const [script, calledArgs] = crossSpawnFirstCall || ['', []]
       expect([script, ...calledArgs].join(' ')).toMatchSnapshot()
     } catch (error) {
       throw error
@@ -58,6 +57,9 @@ cases(
         }
       }),
     },
+    'exits if there are no scripts to be run': {
+      setup: withDefaultSetup(setupWithScripts([])),
+    },
   },
 )
 

src/scripts/validate.js

@@ -27,10 +27,16 @@ const scripts = useDefaultScripts
       return scriptsToRun
     }, {})
 
-const result = spawn.sync(
-  resolveBin('concurrently'),
-  getConcurrentlyArgs(scripts),
-  {stdio: 'inherit'},
-)
+const scriptCount = Object.values(scripts).filter(Boolean).length
 
-process.exit(result.status)
+if (scriptCount > 0) {
+  const result = spawn.sync(
+    resolveBin('concurrently'),
+    getConcurrentlyArgs(scripts),
+    {stdio: 'inherit'},
+  )
+
+  process.exit(result.status)
+} else {
+  process.exit(0)
+}