Preserve stderr/stdout when the command fails early

Author: henryju

lib/src/main/java/org/sonarsource/scanner/lib/internal/facade/forked/JavaRunner.java

@@ -56,15 +56,17 @@ public boolean execute(List<String> args, @Nullable String input, Consumer<Strin
         LOG.debug("Executing: {}", String.join(" ", command));
       }
       Process process = new ProcessBuilder(command).start();
+      var stdoutConsummer = new StreamGobbler(process.getInputStream(), stdOutConsummer);
+      var stdErrConsummer = new StreamGobbler(process.getErrorStream(), stderr -> LOG.error("[stderr] {}", stderr));
+      stdErrConsummer.start();
+      stdoutConsummer.start();
       if (input != null) {
         try (var stdin = process.getOutputStream(); var osw = new OutputStreamWriter(stdin, StandardCharsets.UTF_8)) {
           osw.write(input);
+        } catch (IOException e) {
+          LOG.debug("Failed to write to the Java command stdin", e);
         }
       }
-      var stdoutConsummer = new StreamGobbler(process.getInputStream(), stdOutConsummer);
-      var stdErrConsummer = new StreamGobbler(process.getErrorStream(), stderr -> LOG.error("[stderr] {}", stderr));
-      stdErrConsummer.start();
-      stdoutConsummer.start();
       var exitCode = process.waitFor();
       stdoutConsummer.join();
       stdErrConsummer.join();

lib/src/test/java/org/sonarsource/scanner/lib/internal/facade/forked/JavaRunnerTest.java

@@ -68,6 +68,16 @@ void execute_whenInvalidRunner_shouldFail() {
       .hasMessageContaining("Failed to run the Java command");
   }
 
+  @Test
+  void execute_whenReturnEarly_shouldLogUnableToWriteToStdin() {
+    JavaRunner runner = new JavaRunner(Paths.get("java"), JreCacheHit.DISABLED);
+    List<String> command = List.of("-xyz");
+    assertThat(runner.execute(command, "test", stdOut::add)).isFalse();
+
+    assertThat(logTester.logs(Level.DEBUG)).isNotEmpty().contains("Failed to write to the Java command stdin");
+    assertThat(logTester.logs(Level.ERROR)).isNotEmpty().anyMatch(s -> s.startsWith("[stderr] Unrecognized option: -xyz"));
+  }
+
   @Test
   void execute_shouldReturnFalseWhenNonZeroExitCode() {
     JavaRunner runner = new JavaRunner(Paths.get("java"), JreCacheHit.DISABLED);