Adding a method to retrieve resultFileResources from gcloud easily (#64)

* Adding a method to retieve resultFileResources from gcloud easily

* Updating to use gcsPath directly

* adding null check if path doesn't exist

* addressing feedback

Author: rnakade

AndroidXCI/lib/src/main/kotlin/dev/androidx/ci/gcloud/GoogleCloudApi.kt

@@ -78,6 +78,12 @@ internal interface GoogleCloudApi {
      * Walks all entries under the given [gcsPath].
      */
     suspend fun walkEntries(gcsPath: GcsPath): Sequence<BlobVisitor>
+
+    /**
+     * Gets the blobvisitor for the given [gcsPath] if the gcsPath represents a file.
+     * Returns null if the gcsPath points to a folder
+     */
+    suspend fun getBlob(gcsPath: GcsPath): BlobVisitor?
 }
 
 /**
@@ -193,6 +199,19 @@ private class GoogleCloudApiImpl(
         }
     }
 
+    override suspend fun getBlob(
+        gcsPath: GcsPath
+    ): BlobVisitor? {
+        val blobId = gcsPath.blobId
+        val blob = service.get(blobId)
+        return if (blob != null) {
+            BlobVisitorImpl(
+                rootBlobId = blobId,
+                blob = blob
+            )
+        } else null
+    }
+
     override suspend fun existingFilePath(relativePath: String): GcsPath? {
         val blobId = createBlobId(relativePath)
         val blob = service.get(blobId)

AndroidXCI/lib/src/main/kotlin/dev/androidx/ci/testRunner/TestRunnerService.kt

@@ -104,6 +104,14 @@ interface TestRunnerService {
         testIdentifiers: List<TestIdentifier>
     ): Map<TestIdentifier, List<TestCaseArtifact>>?
 
+    /**
+     * Gets the resultFileResource represented by the [GcsPath]
+     * Returns null if gcsPath points to a folder
+     */
+    suspend fun getResultFileResource(
+        gcsPath: GcsPath
+    ): ResultFileResource?
+
     companion object {
         /**
          * Creates an implementation of [TestRunnerService].

AndroidXCI/lib/src/main/kotlin/dev/androidx/ci/testRunner/TestRunnerServiceImpl.kt

@@ -229,9 +229,6 @@ internal class TestRunnerServiceImpl internal constructor(
                     visitor.fileName.startsWith(testName)
                 }
                 val testIdentifier = testNames[testName]
-                println("filename =  ${visitor.fileName}")
-                println("testName = $testName")
-                println("testIdentifier = $testIdentifier")
                 if (testIdentifier != null) {
                     testArtifactsBlobs.getOrPut(testIdentifier) {
                         mutableListOf()
@@ -247,6 +244,16 @@ internal class TestRunnerServiceImpl internal constructor(
         return testArtifactsBlobs
     }
 
+    override suspend fun getResultFileResource(
+        gcsPath: GcsPath
+    ): TestRunnerService.ResultFileResource? {
+        return googleCloudApi.getBlob(gcsPath)?.let { blobVisitor ->
+            ResultFileResourceImpl(
+                blobVisitor
+            )
+        }
+    }
+
     suspend fun getTestMatrixResults(
         testMatrixId: String
     ): List<TestRunnerService.TestRunResult>? {

AndroidXCI/lib/src/test/kotlin/dev/androidx/ci/fake/FakeGoogleCloudApi.kt

@@ -64,6 +64,20 @@ internal class FakeGoogleCloudApi(
         }
     }
 
+    override suspend fun getBlob(gcsPath: GcsPath): BlobVisitor? {
+        return if (artifacts.containsKey(gcsPath)) {
+            object : BlobVisitor {
+                override val relativePath: String
+                    get() = ""
+                override val gcsPath: GcsPath
+                    get() = gcsPath
+                override fun obtainInputStream(): InputStream {
+                    return artifacts[gcsPath]?.inputStream() ?: InputStream.nullInputStream()
+                }
+            }
+        } else null
+    }
+
     override suspend fun existingFilePath(relativePath: String): GcsPath? {
         val path = makeGcsPath(relativePath)
         return if (artifacts.containsKey(path)) {

AndroidXCI/lib/src/test/kotlin/dev/androidx/ci/testRunner/TestRunnerServiceImplTest.kt

@@ -2,6 +2,7 @@ package dev.androidx.ci.testRunner
 
 import com.google.common.truth.Truth.assertThat
 import dev.androidx.ci.fake.FakeBackend
+import dev.androidx.ci.gcloud.GcsPath
 import dev.androidx.ci.generated.ftl.ClientInfo
 import dev.androidx.ci.generated.ftl.ClientInfoDetail
 import dev.androidx.ci.generated.ftl.EnvironmentMatrix
@@ -101,6 +102,56 @@ class TestRunnerServiceImplTest {
         ).isEqualTo(3)
     }
 
+    @Test
+    fun getBlob() = runBlocking {
+        // load some data into the backend
+        val resultRelativePath = "my-test-matrix-results"
+        val resultPath = "${fakeBackend.fakeGoogleCloudApi.rootGcsPath}/$resultRelativePath"
+        fakeBackend.fakeGoogleCloudApi.upload(
+            "$resultRelativePath/test1",
+            "test1".toByteArray(Charsets.UTF_8)
+        )
+
+        // verify file existing in backend is returned
+        val test1 = fakeBackend.fakeGoogleCloudApi.getBlob(
+            GcsPath("$resultPath/test1")
+        )
+        assertThat(test1).isNotNull()
+        assertThat(test1?.gcsPath?.path).isEqualTo("$resultPath/test1")
+        assertThat(
+            subject.getResultFileResource(
+                GcsPath("$resultPath/test1")
+            )?.readFully()
+        ).isNotEmpty()
+
+        assertThat(
+            subject.getResultFileResource(
+                GcsPath("$resultPath/test1")
+            )?.readFully()
+        ).isEqualTo("test1".toByteArray(Charsets.UTF_8))
+
+        // no blob should be returned for a folder
+        val test2 = fakeBackend.fakeGoogleCloudApi.getBlob(
+            GcsPath(resultPath)
+        )
+        assertThat(test2).isNull()
+        assertThat(
+            subject.getResultFileResource(
+                GcsPath(resultPath)
+            )?.readFully()
+        ).isNull()
+
+        // no blob should be returned for files that don't exist in backend
+        val test3 = fakeBackend.fakeGoogleCloudApi.getBlob(
+            GcsPath("$resultPath/test3")
+        )
+        assertThat(test3).isNull()
+        assertThat(
+            subject.getResultFileResource(
+                GcsPath("$resultPath/test3")
+            )?.readFully()
+        ).isNull()
+    }
     @Test
     fun schedule() = runBlocking<Unit> {
         val apk1Bytes = byteArrayOf(1, 2, 3, 4, 5)