Keep going if a file cannot be read

and report a non-zero exit status, similar to handling of syntax errors.

MOE_MIGRATED_REVID=222038590

Author: manuelF

core/src/main/java/com/google/googlejavaformat/java/Main.java

@@ -111,6 +111,8 @@ private int formatFiles(CommandLineOptions parameters, JavaFormatterOptions opti
 
     Map<Path, String> inputs = new LinkedHashMap<>();
     Map<Path, Future<String>> results = new LinkedHashMap<>();
+    boolean allOk = true;
+
     for (String fileName : parameters.files()) {
       if (!fileName.endsWith(".java")) {
         errWriter.println("Skipping non-Java file: " + fileName);
@@ -120,15 +122,15 @@ private int formatFiles(CommandLineOptions parameters, JavaFormatterOptions opti
       String input;
       try {
         input = new String(Files.readAllBytes(path), UTF_8);
+        inputs.put(path, input);
+        results.put(
+            path, executorService.submit(new FormatFileCallable(parameters, input, options)));
       } catch (IOException e) {
         errWriter.println(fileName + ": could not read file: " + e.getMessage());
-        return 1;
+        allOk = false;
       }
-      inputs.put(path, input);
-      results.put(path, executorService.submit(new FormatFileCallable(parameters, input, options)));
     }
 
-    boolean allOk = true;
     for (Map.Entry<Path, Future<String>> result : results.entrySet()) {
       Path path = result.getKey();
       String formatted;

core/src/test/java/com/google/googlejavaformat/java/FormatterTest.java

@@ -83,8 +83,8 @@ public void testFormatNonJavaFiles() throws Exception {
     assertThat(main.format("foo.go")).isEqualTo(0);
     assertThat(err.toString()).contains("Skipping non-Java file: " + "foo.go");
 
-    // should fail because the file does not exist
-    assertThat(main.format("Foo.java")).isNotEqualTo(0);
+    // format still fails on missing files
+    assertThat(main.format("Foo.java")).isEqualTo(1);
     assertThat(err.toString()).contains("Foo.java: could not read file: ");
   }
 

core/src/test/java/com/google/googlejavaformat/java/MainTest.java

@@ -22,6 +22,7 @@
 import com.google.common.io.ByteStreams;
 import java.io.BufferedWriter;
 import java.io.ByteArrayInputStream;
+import java.io.File;
 import java.io.InputStream;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
@@ -393,6 +394,38 @@ public void dryRunFiles() throws Exception {
     assertThat(err.toString()).isEmpty();
   }
 
+  @Test
+  public void keepGoingWhenFilesDontExist() throws Exception {
+    Path a = testFolder.newFile("A.java").toPath();
+    Path b = testFolder.newFile("B.java").toPath();
+    File cFile = testFolder.newFile("C.java");
+    Path c = cFile.toPath();
+    cFile.delete();
+
+    Files.write(a, "class A{}\n".getBytes(UTF_8));
+    Files.write(b, "class B{}\n".getBytes(UTF_8));
+
+    StringWriter out = new StringWriter();
+    StringWriter err = new StringWriter();
+    Main main = new Main(new PrintWriter(out, true), new PrintWriter(err, true), System.in);
+
+    int exitCode =
+        main.format(
+            "",
+            a.toAbsolutePath().toString(),
+            c.toAbsolutePath().toString(),
+            b.toAbsolutePath().toString());
+
+    // Formatter returns failure if a file was not present.
+    assertThat(exitCode).isEqualTo(1);
+
+    // Present files were correctly formatted.
+    assertThat(out.toString()).isEqualTo("class A {}\nclass B {}\n");
+
+    // File not found still showed error.
+    assertThat(err.toString()).isNotEmpty();
+  }
+
   @Test
   public void exitIfChangedStdin() throws Exception {
     Path path = testFolder.newFile("Test.java").toPath();