codewhisperer: update open tabs logic to prioritize files with lower file distances (#3744)

Author: Will-ShaoHua

jetbrains-core/src/software/aws/toolkits/jetbrains/services/codewhisperer/util/CodeWhispererFileCrawler.kt

@@ -91,5 +91,30 @@ abstract class CodeWhispererFileCrawler : FileCrawler {
                 acc
             }
         }
+
+        /**
+         * For [LocalFileSystem](implementation of virtual file system), the path will be an absolute file path with file separator characters replaced
+         * by forward slash "/"
+         * @see [VirtualFile.getPath]
+         */
+        fun getFileDistance(targetFile: VirtualFile, candidateFile: VirtualFile): Int {
+            val targetFilePaths = targetFile.path.split("/").dropLast(1)
+            val candidateFilePaths = candidateFile.path.split("/").dropLast(1)
+
+            var i = 0
+            while (i < minOf(targetFilePaths.size, candidateFilePaths.size)) {
+                val dir1 = targetFilePaths[i]
+                val dir2 = candidateFilePaths[i]
+
+                if (dir1 != dir2) {
+                    break
+                }
+
+                i++
+            }
+
+            return targetFilePaths.subList(fromIndex = i, toIndex = targetFilePaths.size).size +
+                candidateFilePaths.subList(fromIndex = i, toIndex = candidateFilePaths.size).size
+        }
     }
 }

jetbrains-core/src/software/aws/toolkits/jetbrains/services/codewhisperer/util/JavaCodeWhispererFileCrawler.kt

@@ -25,10 +25,20 @@ object JavaCodeWhispererFileCrawler : CodeWhispererFileCrawler() {
 
     override fun guessSourceFileName(tstFileName: String): String = tstFileName.substring(0, tstFileName.length - "Test.java".length) + ".java"
 
-    override fun listRelevantFilesInEditors(psiFile: PsiFile): List<VirtualFile> = FileEditorManager.getInstance(psiFile.project).openFiles.toList().filter {
-        it.name != psiFile.virtualFile.name &&
-            it.extension == psiFile.virtualFile.extension &&
-            !TestSourcesFilter.isTestSources(it, psiFile.project)
+    override fun listRelevantFilesInEditors(psiFile: PsiFile): List<VirtualFile> {
+        val targetFile = psiFile.virtualFile
+
+        val openedFiles = FileEditorManager.getInstance(psiFile.project).openFiles.toList().filter {
+            it.name != psiFile.virtualFile.name &&
+                it.extension == psiFile.virtualFile.extension &&
+                !TestSourcesFilter.isTestSources(it, psiFile.project)
+        }
+
+        val fileToFileDistanceList = openedFiles.map {
+            return@map it to CodeWhispererFileCrawler.getFileDistance(targetFile = targetFile, candidateFile = it)
+        }
+
+        return fileToFileDistanceList.sortedBy { it.second }.map { it.first }
     }
 
     override suspend fun listFilesImported(psiFile: PsiFile): List<VirtualFile> {

jetbrains-core/tst/software/aws/toolkits/jetbrains/services/codewhisperer/CodeWhispererFileCrawlerTest.kt

@@ -45,6 +45,65 @@ class JavaCodeWhispererFileCrawlerTest : CodeWhispererFileCrawlerTest(JavaCodeIn
         sut = JavaCodeWhispererFileCrawler
     }
 
+    @Test
+    fun getFileDistance() {
+        val targetFile = fixture.addFileToProject("service/microService/CodeWhispererFileContextProvider.java", aString())
+
+        val fileWithDistance0 = fixture.addFileToProject("service/microService/CodeWhispererFileCrawler.java", aString())
+        val fileWithDistance1 = fixture.addFileToProject("service/CodewhispererRecommendationService.java", aString())
+        val fileWithDistance3 = fixture.addFileToProject("util/CodeWhispererConstants.java", aString())
+        val fileWithDistance4 = fixture.addFileToProject("ui/popup/CodeWhispererPopupManager.java", aString())
+        val fileWithDistance5 = fixture.addFileToProject("ui/popup/components/CodeWhispererPopup.java", aString())
+        val fileWithDistance6 = fixture.addFileToProject("ui/popup/components/actions/AcceptRecommendationAction.java", aString())
+
+        assertThat(CodeWhispererFileCrawler.getFileDistance(targetFile.virtualFile, fileWithDistance0.virtualFile))
+            .isEqualTo(0)
+
+        assertThat(CodeWhispererFileCrawler.getFileDistance(targetFile.virtualFile, fileWithDistance1.virtualFile))
+            .isEqualTo(1)
+
+        assertThat(CodeWhispererFileCrawler.getFileDistance(targetFile.virtualFile, fileWithDistance3.virtualFile))
+            .isEqualTo(3)
+
+        assertThat(CodeWhispererFileCrawler.getFileDistance(targetFile.virtualFile, fileWithDistance4.virtualFile))
+            .isEqualTo(4)
+
+        assertThat(CodeWhispererFileCrawler.getFileDistance(targetFile.virtualFile, fileWithDistance5.virtualFile))
+            .isEqualTo(5)
+
+        assertThat(CodeWhispererFileCrawler.getFileDistance(targetFile.virtualFile, fileWithDistance6.virtualFile))
+            .isEqualTo(6)
+    }
+
+    @Test
+    fun listRelevantFilesInEditor() {
+        val recommendationServiceFile = fixture.addFileToProject("service/CodewhispererRecommendationService.java", aString())
+        val fileContextProviderFile = fixture.addFileToProject("service/microService/CodeWhispererFileContextProvider.java", aString())
+        val constantFile = fixture.addFileToProject("util/CodeWhispererConstants.java", aString())
+        val popupManagerFile = fixture.addFileToProject("ui/popup/CodeWhispererPopupManager.java", aString())
+        val popupFile = fixture.addFileToProject("ui/popup/components/CodeWhispererPopup.java", aString())
+        val popupActionFile = fixture.addFileToProject("ui/popup/components/actions/AcceptRecommendationAction.java", aString())
+
+        val files = listOf(recommendationServiceFile, fileContextProviderFile, constantFile, popupManagerFile, popupFile, popupActionFile)
+
+        files.shuffled().forEach {
+            runInEdtAndWait {
+                fixture.openFileInEditor(it.virtualFile)
+            }
+        }
+
+        val actual = sut.listRelevantFilesInEditors(fileContextProviderFile)
+        assertThat(actual).isEqualTo(
+            listOf(
+                recommendationServiceFile.virtualFile,
+                constantFile.virtualFile,
+                popupManagerFile.virtualFile,
+                popupFile.virtualFile,
+                popupActionFile.virtualFile
+            )
+        )
+    }
+
     @Test
     fun `findFilesUnderProjectRoot`() {
         val mainClass = fixture.addFileToProject(