From 4c2dc787c08c9dc657a832302179c2d37b65af75 Mon Sep 17 00:00:00 2001
From: Ashley Scopes <73482956+ascopes@users.noreply.github.com>
Date: Sun, 12 May 2024 16:00:57 +0100
Subject: [PATCH] Warn ahead of time if directories are missing and omit them
 from compilation

---
 .../mojo/AbstractGenerateMojo.java            |  8 +++++
 .../AbstractGenerateMojoTestTemplate.java     | 30 +++++++++++++++++--
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojo.java b/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojo.java
index f5ce0294..883f1863 100644
--- a/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojo.java
+++ b/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojo.java
@@ -32,6 +32,7 @@
 import io.github.ascopes.protobufmavenplugin.plugins.UrlProtocPluginBean;
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Collection;
 import java.util.List;
@@ -673,6 +674,13 @@ private Collection<Path> sourceDirectories() {
         .stream()
         .flatMap(Collection::stream)
         .map(File::toPath)
+        .filter(path -> {
+          if (Files.notExists(path)) {
+            log.warn("Ignoring source directory {} as it does not appear to exist", path);
+            return false;
+          }
+          return true;
+        })
         .collect(Collectors.toList());
 
     return transformedSourceDirectories.isEmpty()
diff --git a/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojoTestTemplate.java b/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojoTestTemplate.java
index 4749cd48..a013adc1 100644
--- a/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojoTestTemplate.java
+++ b/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/mojo/AbstractGenerateMojoTestTemplate.java
@@ -41,6 +41,7 @@
 import io.github.ascopes.protobufmavenplugin.plugins.UrlProtocPluginBean;
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.EnumSet;
 import java.util.List;
@@ -747,9 +748,9 @@ void whenSourceDirectoriesProvidedExpectPathsInRequest(
         @TempDir Path someTempDir
     ) throws Throwable {
       // Given
-      var path1 = someTempDir.resolve("foo").resolve("bar");
-      var path2 = someTempDir.resolve("do").resolve("ray");
-      var path3 = someTempDir.resolve("aaa").resolve("bbb");
+      var path1 = Files.createDirectories(someTempDir.resolve("foo").resolve("bar"));
+      var path2 = Files.createDirectories(someTempDir.resolve("do").resolve("ray"));
+      var path3 = Files.createDirectories(someTempDir.resolve("aaa").resolve("bbb"));
 
       mojo.sourceDirectories = List.of(path1.toFile(), path2.toFile(), path3.toFile());
 
@@ -762,6 +763,29 @@ void whenSourceDirectoriesProvidedExpectPathsInRequest(
       var actualRequest = captor.getValue();
       assertThat(actualRequest.getSourceRoots()).containsExactly(path1, path2, path3);
     }
+
+    @DisplayName("missing sourceDirectories are not provided to the generator")
+    @Test
+    void missingSourceDirectoriesAreNotProvidedToTheGenerator(
+        @TempDir Path someTempDir
+    ) throws Throwable {
+      // Given
+      var path1 = Files.createDirectories(someTempDir.resolve("foo").resolve("bar"));
+      var path2 = someTempDir.resolve("do").resolve("ray");
+      var path3 = Files.createDirectories(someTempDir.resolve("aaa").resolve("bbb"));
+      assertThat(path2).doesNotExist();
+
+      mojo.sourceDirectories = List.of(path1.toFile(), path2.toFile(), path3.toFile());
+
+      // When
+      mojo.execute();
+
+      // Then
+      var captor = ArgumentCaptor.forClass(GenerationRequest.class);
+      verify(mojo.sourceCodeGenerator).generate(captor.capture());
+      var actualRequest = captor.getValue();
+      assertThat(actualRequest.getSourceRoots()).containsExactly(path1, path3);
+    }
   }
 
   @DisplayName("languages are enabled and disabled as expected")