Surface Detekt stderr output for test targets

Author: ryanulep

.bazelrc

@@ -1,8 +1,8 @@
 common --test_tag_filters=-manual
 
-# abseil-cpp and protobuf (pulled in by stardoc) use std::visit/std::get with std::variant,
-# which requires macOS 10.13+. Set the minimum OS for both target and host/exec tool builds.
-# Uncomment the below if running into Stardoc issues on Mac.
+# abseil-cpp and protobuf use std::visit/std::get with std::variant, which requires macOS 10.13+.
+# Set the minimum OS for both target and host/exec tool builds.
+# Uncomment the below if running into issues on Mac.
 # build --macos_minimum_os=10.13
 # build --host_macos_minimum_os=10.13
 

detekt/defs.bzl

@@ -280,6 +280,11 @@ def _impl(
     action_outputs.append(execution_result)
     detekt_arguments.add("--execution-result", "{}".format(execution_result.path))
 
+    stderr_output = ctx.actions.declare_file("{}_stderr.txt".format(ctx.label.name))
+    run_files.append(stderr_output)
+    action_outputs.append(stderr_output)
+    detekt_arguments.add("--stderr-output", "{}".format(stderr_output.path))
+
     ctx.actions.run(
         mnemonic = "Detekt",
         progress_message = "Running Detekt for {}".format(str(ctx.label)),
@@ -304,13 +309,13 @@ def _impl(
 #!/bin/bash
 set -euo pipefail
 exit_code=$(cat {execution_result})
-report=$(cat {text_report})
-if [ ! -z "$report" ]; then
-    echo "$report"
+stderr_content=$(cat {stderr_output})
+if [ ! -z "$stderr_content" ]; then
+    echo "$stderr_content"
 fi
 {baseline_script}
 exit "$exit_code"
-""".format(execution_result = execution_result.short_path, text_report = txt_report.short_path, baseline_script = baseline_script),
+""".format(execution_result = execution_result.short_path, stderr_output = stderr_output.short_path, baseline_script = baseline_script),
         is_executable = True,
     )
 

detekt/wrapper/src/main/java/io/buildfoundation/bazel/detekt/ExecutionUtils.java

@@ -40,6 +40,15 @@ public static void writeExecutionResultToFile(Integer exitCode, Path executionRe
         }
     }
 
+  /** Writes the stderr output to a file */
+  public static void writeStderrToFile(String stderrContent, Path stderrOutputPath) {
+    try {
+      Files.write(stderrOutputPath, stderrContent.getBytes(), StandardOpenOption.CREATE);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
     public static boolean isParamsFile(String argument) {
         return argument.startsWith("@");
     }
@@ -55,14 +64,14 @@ public static List<String> readArgumentsFromFile(Path filePath) {
         }
     }
 
-    /**
-     * Retrieves the value associated with the given argument name from the input arguments list.
-     *
-     * @param inputArgs List of input arguments.
-     * @param argName The name of the argument whose value needs to be fetched.
-     * @return The value associated with the given argument name or null if the argument is not found.
-     */
-    public static String getValueForArgumentName(List<String> inputArgs, String argName) {
+  /**
+   * Retrieves the value associated with the given argument name from the input arguments list.
+   *
+   * @param inputArgs List of input arguments.
+   * @param argName The name of the argument whose value needs to be fetched.
+   * @return The value associated with the given argument name or null if the argument is not found.
+   */
+  public static String getValueForArgumentName(List<String> inputArgs, String argName) {
         try {
             // Get the index of the argument and return the value at the next index.
             int indexOfArgument = inputArgs.indexOf(argName);
@@ -80,7 +89,9 @@ public static String getValueForArgumentName(List<String> inputArgs, String argN
      * Sanitizes the Detekt arguments by excluding arguments used solely by the detekt-wrapper
      */
     public static List<String> sanitizeDetektArguments(List<String> inputArgs) {
-        Set<String> excludedArgs = new HashSet<>(Arrays.asList("--execution-result", "--run-as-test-target"));
+    Set<String> excludedArgs =
+        new HashSet<>(
+            Arrays.asList("--execution-result", "--run-as-test-target", "--stderr-output"));
         return filterOutArgValuePairs(inputArgs, excludedArgs);
     }
 

detekt/wrapper/src/main/java/io/buildfoundation/bazel/detekt/execute/Executable.java

@@ -68,6 +68,13 @@ public ExecutableResult execute(String[] args) {
 
             ExecutionUtils.writeExecutionResultToFile(result.statusCode(), executionResultOutputPath);
 
+            String stderrOutputPathStr =
+                    ExecutionUtils.getValueForArgumentName(detektWrapperArguments, "--stderr-output");
+            if (stderrOutputPathStr != null) {
+                Path stderrOutputPath = Paths.get(stderrOutputPathStr);
+                ExecutionUtils.writeStderrToFile(result.output(), stderrOutputPath);
+            }
+
             if (ExecutionUtils.shouldRunAsTestTarget(detektWrapperArguments)) {
                 result = new ExecutableResult.Success();
             }

tests/analysis/tests.bzl

@@ -84,6 +84,7 @@ def _action_full_contents_test_impl(ctx):
         "{{source_dir}}/test_target_full_detekt_report.html",
         "{{source_dir}}/test_target_full_detekt_report.xml",
         "{{source_dir}}/test_target_full_exit_code.txt",
+        "{{source_dir}}/test_target_full_stderr.txt",
     ])
 
     asserts.equals(env, expected_inputs, [file.short_path for file in action.inputs.to_list()])
@@ -143,6 +144,7 @@ def _action_blank_contents_test_impl(ctx):
     expected_outputs = _expand_paths(env.ctx, [
         "{{source_dir}}/test_target_blank_detekt_report.txt",
         "{{source_dir}}/test_target_blank_exit_code.txt",
+        "{{source_dir}}/test_target_blank_stderr.txt",
     ])
 
     asserts.equals(env, expected_inputs, [file.short_path for file in action.inputs.to_list()])

tests/integration/BUILD

@@ -1,11 +1,18 @@
-load("//detekt:defs.bzl", "detekt")
+load("//detekt:defs.bzl", "detekt", "detekt_create_baseline")
 
 filegroup(
     name = "detekt_config_lenient",
     srcs = ["detekt_config_lenient.yml"],
     tags = ["manual"],
 )
 
+detekt_create_baseline(
+    name = "create_integration_test_detekt_baseline",
+    srcs = glob(["src/main/kotlin/**/*.kt"]),
+    baseline = "detekt_baseline.xml",
+    tags = ["manual"],
+)
+
 detekt(
     name = "detekt_without_config",
     srcs = glob(["src/main/kotlin/**/*.kt"]),