make output file optional and create output file if necessary

Author: nahsra

framework/codemodder-base/src/main/java/io/codemodder/CLI.java

@@ -274,20 +274,25 @@ public Integer call() throws IOException {
     logEnteringPhase(Logs.ExecutionPhase.STARTING);
     log.info("codemodder: java/{}", CLI.class.getPackage().getImplementationVersion());
 
-    if (output == null) {
-      log.error("The output file is required");
-      return ERROR_CANT_WRITE_OUTPUT_FILE;
-    }
-
     if (projectDirectory == null) {
       log.error("No project directory specified");
       return ERROR_CANT_READ_PROJECT_DIRECTORY;
     }
 
-    Path outputPath = output.toPath();
-    if (!Files.isWritable(outputPath) && !Files.isWritable(outputPath.getParent())) {
-      log.error("The output file (or its parent directory) is not writable");
-      return ERROR_CANT_WRITE_OUTPUT_FILE;
+    Path outputPath = null;
+    if (output != null) {
+      outputPath = output.toPath();
+
+      // check if the output file parent directory doesn't exist
+      if (!Files.exists(outputPath.getParent())) {
+        // create it
+        Files.createDirectories(outputPath.getParent());
+      }
+
+      if (!Files.isWritable(outputPath) && !Files.isWritable(outputPath.getParent())) {
+        log.error("The output file (or its parent directory) is not writable");
+        return ERROR_CANT_WRITE_OUTPUT_FILE;
+      }
     }
 
     Path projectPath = projectDirectory.toPath();
@@ -454,23 +459,25 @@ public Integer call() throws IOException {
       logEnteringPhase(Logs.ExecutionPhase.REPORT);
       logMetrics(results);
 
-      // write out the output
-      if (OutputFormat.CODETF.equals(outputFormat)) {
-        CodeTFReport report =
-            reportGenerator.createReport(
-                projectDirectory.toPath(),
-                String.join(" ", args),
-                sarifs == null
-                    ? List.of()
-                    : sarifs.stream().map(Path::of).collect(Collectors.toList()),
-                results,
-                elapsed);
-        ObjectMapper mapper = new ObjectMapper();
-        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
-        Files.writeString(outputPath, mapper.writeValueAsString(report));
-        log.debug("report file: {}", outputPath);
-      } else if (OutputFormat.DIFF.equals(outputFormat)) {
-        throw new UnsupportedOperationException("not supported yet");
+      // write out the output if they want it
+      if (outputPath != null) {
+        if (OutputFormat.CODETF.equals(outputFormat)) {
+          CodeTFReport report =
+              reportGenerator.createReport(
+                  projectDirectory.toPath(),
+                  String.join(" ", args),
+                  sarifs == null
+                      ? List.of()
+                      : sarifs.stream().map(Path::of).collect(Collectors.toList()),
+                  results,
+                  elapsed);
+          ObjectMapper mapper = new ObjectMapper();
+          mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+          Files.writeString(outputPath, mapper.writeValueAsString(report));
+          log.debug("report file: {}", outputPath);
+        } else if (OutputFormat.DIFF.equals(outputFormat)) {
+          throw new UnsupportedOperationException("not supported yet");
+        }
       }
 
       log.debug("elapsed: {}ms", elapsed);

framework/codemodder-base/src/test/java/io/codemodder/CLITest.java

@@ -61,6 +61,23 @@ void setup(final @TempDir Path tmpDir) throws IOException {
                 List.of(barJavaFile.toAbsolutePath().toString())));
   }
 
+  @Test
+  void it_works_normally() throws IOException {
+    Path outputFile = Files.createTempFile("codetf", ".json");
+    String[] args =
+        new String[] {"--dont-exit", "--output", outputFile.toString(), workingRepoDir.toString()};
+    Runner.run(List.of(Cloud9Changer.class), args);
+    assertThat(Files.readString(fooJavaFile)).contains("cloud9");
+    assertThat(Files.exists(outputFile)).isTrue();
+  }
+
+  @Test
+  void it_works_without_output_file() throws IOException {
+    String[] args = new String[] {"--dont-exit", workingRepoDir.toString()};
+    Runner.run(List.of(Cloud9Changer.class), args);
+    assertThat(Files.readString(fooJavaFile)).contains("cloud9");
+  }
+
   /**
    * Runs the CLI with arguments that we know will cause it to fail, and asserts that the exit code
    * denotes failure and an error message is captured in the alternative stderr stream.
@@ -107,6 +124,17 @@ private static void writeLogMessageToFile(final Path outputFile, final String pr
     log.info("this is a test");
   }
 
+  @Test
+  void output_file_parent_dirs_created() throws IOException {
+    Path normalCodetf = Files.createTempDirectory("exists");
+    Path outputFile = normalCodetf.resolve("doesnt/exist/codetf.json");
+    String[] args =
+        new String[] {"--dont-exit", "--output", outputFile.toString(), workingRepoDir.toString()};
+    Runner.run(List.of(Cloud9Changer.class), args);
+    assertThat(Files.readString(fooJavaFile)).contains("cloud9");
+    assertThat(Files.exists(outputFile)).isTrue();
+  }
+
   @Test
   void dry_run_works() throws IOException {
     Path normalCodetf = Files.createTempFile("normal", ".codetf");