Stop re-running tests when mtime has not changed

CHANGELOG.md

@@ -13,6 +13,7 @@
 - `[jest-circus]` [**BREAKING**] Fail tests if a test takes a done callback and have return values ([#9129](https://github.com/facebook/jest/pull/9129))
 - `[jest-circus]` [**BREAKING**] Throw a proper error if a test / hook is defined asynchronously ([#8096](https://github.com/facebook/jest/pull/8096))
 - `[jest-config, jest-resolve]` [**BREAKING**] Remove support for `browser` field ([#9943](https://github.com/facebook/jest/pull/9943))
+- `[jest-haste-map]` Stop reporting files as changed when they are only accessed ([#7347](https://github.com/facebook/jest/pull/7347))
 - `[jest-resolve]` Show relative path from root dir for `module not found` errors ([#9963](https://github.com/facebook/jest/pull/9963))
 
 ### Chore & Maintenance

packages/jest-haste-map/src/index.ts

@@ -846,6 +846,19 @@ class HasteMap extends EventEmitter {
         return;
       }
 
+      const relativeFilePath = fastPath.relative(rootDir, filePath);
+      const fileMetadata = hasteMap.files.get(relativeFilePath);
+
+      // The file has been accessed, not modified
+      if (
+        fileMetadata &&
+        type === 'change' &&
+        stat &&
+        fileMetadata[H.MTIME] === stat.mtime.getTime()
+      ) {
+        return;
+      }
+
       changeQueue = changeQueue
         .then(() => {
           // If we get duplicate events for the same file, ignore them.
@@ -879,9 +892,6 @@ class HasteMap extends EventEmitter {
             return null;
           };
 
-          const relativeFilePath = fastPath.relative(rootDir, filePath);
-          const fileMetadata = hasteMap.files.get(relativeFilePath);
-
           // If it's not an addition, delete the file and all its metadata
           if (fileMetadata != null) {
             const moduleName = fileMetadata[H.ID];