Only run pytest if test files are found in the test directories (#5012)

airbyte-integrations/bases/base-python/build.gradle

@@ -14,5 +14,3 @@ dependencies {
 
 installReqs.dependsOn(":airbyte-integrations:bases:airbyte-protocol:installReqs")
 
-// no-op integration test task to allow build script to succeed. TODO fix build script to not require a task with this name.
-task("integrationTest")

airbyte-integrations/bases/base-singer/build.gradle

@@ -14,5 +14,3 @@ dependencies {
 
 installReqs.dependsOn(":airbyte-integrations:bases:airbyte-protocol:installReqs", ":airbyte-integrations:bases:base-python:installReqs")
 
-// no-op integration test task to allow build script to succeed. TODO fix build script to not require a task with this name. 
-task("integrationTest")

airbyte-integrations/bases/source-acceptance-test/build.gradle

@@ -7,5 +7,3 @@ airbytePython {
     moduleDirectory 'source_acceptance_test'
 }
 
-// no-op integration test task to allow build script to succeed. TODO fix build script to not require a task with this name.
-task("integrationTest")

airbyte-integrations/connectors/source-appstore-singer/build.gradle

@@ -8,15 +8,14 @@ airbytePython {
     moduleDirectory 'source_appstore_singer'
 }
 
+// https://github.com/airbytehq/airbyte/issues/1651
 //airbyteStandardSourceTestFile {
 //    // For more information on standard source tests, see https://docs.airbyte.io/contributing-to-airbyte/building-new-connector/testing-connectors
 //    specPath = "source_appstore_singer/spec.json"
 //    configPath = "secrets/config.json"
 //    configuredCatalogPath = "sample_files/configured_catalog.json"
 //}
 
-task("integrationTest") // https://github.com/airbytehq/airbyte/issues/1651
-
 dependencies {
     implementation files(project(':airbyte-integrations:bases:base-standard-source-test-file').airbyteDocker.outputs)
     implementation files(project(':airbyte-integrations:bases:base-singer').airbyteDocker.outputs)

airbyte-integrations/connectors/source-mongodb/build.gradle

@@ -36,3 +36,4 @@ airbyteStandardSourceTestFile {
 dependencies {
     implementation files(project(':airbyte-integrations:bases:base-standard-source-test-file').airbyteDocker.outputs)
 }
+

buildSrc/src/main/groovy/airbyte-python.gradle

@@ -1,3 +1,5 @@
+import groovy.io.FileType
+import groovy.io.FileVisitResult
 import org.gradle.api.GradleException
 import org.gradle.api.Plugin
 import org.gradle.api.Project
@@ -8,6 +10,47 @@ class AirbytePythonConfiguration {
     String moduleDirectory
 }
 
+class Helpers {
+    static addTestTaskIfTestFilesFound(Project project, String testFilesDirectory, String taskName, taskDependencies) {
+        """
+        This method verifies if there are test files in a directory before adding the pytest task to run tests on that directory. This is needed 
+        because if there are no tests in that dir and we run pytest on it, it exits with exit code 5 which gradle takes to mean that the process
+        failed, since it's non-zero. This means that if a module doesn't need a unit or integration test, it still needs to add a dummy test file
+        like: 
+        
+        ```
+        def make_ci_pass_test():
+            assert True
+        ```
+        
+        So we use this method to leverage pytest's test discovery rules (https://docs.pytest.org/en/6.2.x/goodpractices.html#conventions-for-python-test-discovery)
+        to selectively run pytest based on whether there seem to be test files in that directory. 
+        Namely, if the directory contains a file whose name is test_*.py or *_test.py then it's a test. 
+       
+        See https://github.com/airbytehq/airbyte/issues/4979 for original context
+        """
+        if (project.file(testFilesDirectory).exists()) {
+
+            project.projectDir.toPath().resolve(testFilesDirectory).traverse(type: FileType.FILES, nameFilter: ~/(^test_.*|.*_test)\.py$/) { file ->
+                project.task(taskName, type: PythonTask, dependsOn: taskDependencies) {
+                    module = "pytest"
+                    command = "-s ${testFilesDirectory}"
+                }
+                // If a file is found, terminate the traversal, thus causing this task to be declared at most once
+                return FileVisitResult.TERMINATE
+            }
+        }
+
+        // If the task doesn't exist then we didn't find a matching file. So add an empty task since other tasks will
+        // probably rely on this one existing.
+        if (!project.hasProperty(taskName)) {
+            project.task(taskName) {
+                logger.info "Skipping task ${taskName} because ${testFilesDirectory} doesn't exist."
+            }
+        }
+    }
+}
+
 class AirbytePythonPlugin implements Plugin<Project> {
 
     void apply(Project project) {
@@ -60,7 +103,7 @@ class AirbytePythonPlugin implements Plugin<Project> {
                     dependsOn project.rootProject.getTasksByName("airbytePythonApply", true).findAll { it.project.getPath().startsWith(":airbyte-integrations:bases") }
                 }
             }
-        } else if(project.file('setup.py').exists()) {
+        } else if (project.file('setup.py').exists()) {
             // If requirements.txt does not exists, install from setup.py instead, assume a dev or "tests" profile exists.
             // In this case, there is no need to depend on the base python modules since everything should be contained in the setup.py.
             project.task('installLocalReqs', type: PythonTask) {
@@ -85,28 +128,12 @@ class AirbytePythonPlugin implements Plugin<Project> {
             outputs.file('build/installedtestreqs.txt')
         }
 
-        if (project.file('unit_tests').exists()) {
-            project.task('unitTest', type: PythonTask, dependsOn: project.installTestReqs) {
-                module = "pytest"
-                command = "-s unit_tests"
-            }
-        } else {
-            project.task('unitTest') {
-                logger.info "Skipping Python unit tests because unit_tests directory doesn't exist."
-            }
-        }
-
-        if (project.file('integration_tests').exists()){
-            project.task('customIntegrationTests', type: PythonTask, dependsOn: project.installTestReqs) {
-                module = "pytest"
-                command = "-s integration_tests"
-            }
-            if (!project.hasProperty('integrationTest')) {
-                project.task('integrationTest')
-            }
-
-            project.integrationTest.dependsOn(project.customIntegrationTests)
+        Helpers.addTestTaskIfTestFilesFound(project, 'unit_tests', 'unitTest', project.installTestReqs)
+        Helpers.addTestTaskIfTestFilesFound(project, 'integration_tests', 'customIntegrationTests', project.installTestReqs)
+        if (!project.tasks.findByName('integrationTest')) {
+            project.task('integrationTest')
         }
+        project.integrationTest.dependsOn(project.customIntegrationTests)
 
         if (extension.moduleDirectory) {
             project.task('mypyCheck', type: PythonTask) {
@@ -136,13 +163,13 @@ class AirbytePythonPlugin implements Plugin<Project> {
         }
 
         // Add a task that allows cleaning up venvs to every python project
-        project.task('cleanPythonVenv', type: Exec){
+        project.task('cleanPythonVenv', type: Exec) {
             commandLine 'rm'
             args '-rf', "$project.projectDir.absolutePath/$venvDirectoryName"
         }
 
         // Add a task which can be run at the root project level to delete all python venvs
-        if (!project.rootProject.hasProperty('cleanPythonVenvs')){
+        if (!project.rootProject.hasProperty('cleanPythonVenvs')) {
             project.rootProject.task('cleanPythonVenvs')
         }
         project.rootProject.cleanPythonVenvs.dependsOn(project.cleanPythonVenv)

buildSrc/src/main/groovy/airbyte-source-acceptance-test.gradle

@@ -35,11 +35,6 @@ class AirbyteSourceAcceptanceTestPlugin implements Plugin<Project> {
             project.sourceAcceptanceTest.dependsOn(project.airbyteDockerTest)
         }
 
-        // make sure we create the integrationTest task once in case a java integration test was already initialized
-        if (!project.hasProperty('integrationTest')) {
-            project.task('integrationTest')
-        }
-
         project.integrationTest.dependsOn(project.sourceAcceptanceTest)
     }
 }

buildSrc/src/main/groovy/airbyte-standard-source-test-file.gradle

@@ -73,7 +73,7 @@ class AirbyteStandardSourceTestFilePlugin implements Plugin<Project> {
         }
 
         // make sure we create the integrationTest task once in case a java integration test was already initialized
-        if (!project.hasProperty('integrationTest')) {
+        if (!project.tasks.findByName('integrationTest')) {
             project.task('integrationTest')
         }