fix: add check for changed lint-staged files before stashing changes

- add test to check if stashing is skipped if no lint-staged files are changed

Fixes lint-staged#570

src/runAll.js

@@ -54,15 +54,21 @@ module.exports = function runAll(config) {
           return `No staged files match ${task.pattern}`
         }
         return false
-      }
+      },
+      hasStagedFiles: () => task.fileList.length > 0
     }))
 
     const listrBaseOptions = {
       dateFormat: false,
       renderer
     }
 
-    if (tasks.length) {
+    let hasStagedTaskFiles = false
+    tasks.forEach(task => {
+      hasStagedTaskFiles = hasStagedTaskFiles || task.hasStagedFiles()
+    })
+
+    if (hasStagedTaskFiles) {
       // Do not terminate main Listr process on SIGINT
       process.on('SIGINT', () => {})
 

test/__snapshots__/runAll.spec.js.snap

@@ -83,6 +83,8 @@ LOG Running tasks for *.js [completed]
 LOG Running linters... [completed]"
 `;
 
+exports[`runAll should skip stashing changes if no lint-staged files are changed 1`] = `""`;
+
 exports[`runAll should skip updating stash if there are errors during linting 1`] = `
 "
 LOG Stashing changes... [started]

test/runAll.spec.js

@@ -161,4 +161,31 @@ describe('runAll', () => {
       expect(err).toEqual('test')
     }
   })
+
+  it.only('should skip stashing changes if no lint-staged files are changed', async () => {
+    expect.assertions(4)
+    hasPartiallyStagedFiles.mockImplementationOnce(() => Promise.resolve(true))
+    sgfMock.mockImplementationOnce((params, callback) => {
+      callback(null, [{ filename: 'sample.java', status: 'Modified' }])
+    })
+    execa.mockImplementationOnce(() =>
+      Promise.resolve({
+        stdout: '',
+        stderr: 'Linter finished with error',
+        code: 1,
+        failed: true,
+        cmd: 'mock cmd'
+      })
+    )
+
+    try {
+      await runAll(getConfig({ linters: { '*.js': ['echo "sample"'] } }))
+    } catch (err) {
+      console.log(err)
+    }
+    expect(console.printHistory()).toMatchSnapshot()
+    expect(gitStashSave).toHaveBeenCalledTimes(0)
+    expect(updateStash).toHaveBeenCalledTimes(0)
+    expect(gitStashPop).toHaveBeenCalledTimes(0)
+  })
 })