Add the ability to configure ignoredFiles (#236)

* Add the ability to configure ignoredFiles

* doc tweak

Author: kpagratis

README.md

@@ -92,6 +92,9 @@ affectedModuleDetector {
     excludedModules = [
         "sample-util", ":(app|library):.+"
     ]
+    ignoredFiles = [
+        ".*\\.md", ".*\\.txt", ".*README"
+    ]
     includeUncommitted = true
     top = "HEAD"
     customTasks = [
@@ -109,6 +112,7 @@ affectedModuleDetector {
  - `logFilename`: A filename for the output detector to use
  - `logFolder`: A folder to output the log file in
  - `specifiedBranch`: A branch to specify changes against. Must be used in combination with configuration `compareFrom = "SpecifiedBranchCommit"` 
+ - `ignoredFiles`: A set of files that will be filtered out of the list of changed files retrieved by git. 
  - `compareFrom`: A commit to compare the branch changes against. Can be either:
     - PreviousCommit: compare against the previous commit
     - ForkCommit: compare against the commit the branch was forked from

affectedmoduledetector/src/main/kotlin/com/dropbox/affectedmoduledetector/AffectedModuleConfiguration.kt

@@ -105,6 +105,11 @@ class AffectedModuleConfiguration {
      */
     var excludedModules = emptySet<String>()
 
+    /**
+     * A set of files that will be filtered out of the list of changed files retrieved by git.
+     */
+    var ignoredFiles = emptySet<String>()
+
     /**
      * If uncommitted files should be considered affected
      */

affectedmoduledetector/src/main/kotlin/com/dropbox/affectedmoduledetector/AffectedModuleDetector.kt

@@ -330,7 +330,8 @@ class AffectedModuleDetectorImpl constructor(
         injectedGitClient ?: GitClientImpl(
             rootProject.projectDir,
             logger,
-            commitShaProvider = CommitShaProvider.fromString(config.compareFrom, config.specifiedBranch)
+            commitShaProvider = CommitShaProvider.fromString(config.compareFrom, config.specifiedBranch),
+            ignoredFiles = config.ignoredFiles
         )
     }
 

affectedmoduledetector/src/main/kotlin/com/dropbox/affectedmoduledetector/GitClient.kt

@@ -72,7 +72,8 @@ internal class GitClientImpl(
         workingDir = workingDir,
         logger = logger
     ),
-    private val commitShaProvider: CommitShaProvider
+    private val commitShaProvider: CommitShaProvider,
+    private val ignoredFiles: Set<String>?
 ) : GitClient {
 
     /**
@@ -85,13 +86,20 @@ internal class GitClientImpl(
         val sha = commitShaProvider.get(commandRunner)
 
         // use this if we don't want local changes
-        return commandRunner.executeAndParse(
+        val changedFiles = commandRunner.executeAndParse(
             if (includeUncommitted) {
                 "$CHANGED_FILES_CMD_PREFIX $sha"
             } else {
                 "$CHANGED_FILES_CMD_PREFIX $top..$sha"
             }
         )
+
+        return ignoredFiles
+            .orEmpty()
+            .map { it.toRegex() }
+            .foldRight(changedFiles){ignoredFileRegex: Regex, fileList: List<String> ->
+                fileList.filterNot { it.matches(ignoredFileRegex) }
+            }
     }
 
     private fun findGitDirInParentFilepath(filepath: File): File? {

affectedmoduledetector/src/test/kotlin/com/dropbox/affectedmoduledetector/GitClientImplTest.kt

@@ -27,17 +27,24 @@ class GitClientImplTest {
         workingDir = workingDir,
         logger = logger,
         commandRunner = commandRunner,
-        commitShaProvider = commitShaProvider
+        commitShaProvider = commitShaProvider,
+        ignoredFiles = setOf(".*\\.ignore", ".*IGNORED_FILE")
     )
 
     @Test
     fun givenChangedFiles_whenFindChangedFilesIncludeUncommitted_thenReturnChanges() {
         val changes = listOf(
+                convertToFilePath("d", "e", ".ignoredNot"),
                 convertToFilePath("a", "b", "c.java"),
                 convertToFilePath("d", "e", "f.java"))
+        val changesWithIgnores = listOf(
+                convertToFilePath("a", "b", "anything.ignore"),
+                convertToFilePath("d", "e", ".ignore"),
+                convertToFilePath("d", "e", "IGNORED_FILE")
+        ) + changes
         commandRunner.addReply(
                 "$CHANGED_FILES_CMD_PREFIX mySha",
-                changes.joinToString(System.lineSeparator())
+            changesWithIgnores.joinToString(System.lineSeparator())
         )
         commitShaProvider.addReply("mySha")
 
@@ -58,11 +65,17 @@ class GitClientImplTest {
     @Test
     fun findChangesSince_twoCls() {
         val changes = listOf(
+                convertToFilePath("d", "e", ".ignoredNot"),
                 convertToFilePath("a", "b", "c.java"),
                 convertToFilePath("d", "e", "f.java"))
+        val changesWithIgnores = listOf(
+                convertToFilePath("a", "b", "anything.ignore"),
+                convertToFilePath("d", "e", ".ignore"),
+                convertToFilePath("d", "e", "IGNORED_FILE")
+        ) + changes
         commandRunner.addReply(
                 "$CHANGED_FILES_CMD_PREFIX otherSha..mySha",
-                changes.joinToString(System.lineSeparator())
+            changesWithIgnores.joinToString(System.lineSeparator())
         )
         commitShaProvider.addReply("mySha")
         assertEquals(