Add config parameter to RevapiExtension

fix #649

Signed-off-by: Sebastian Davids <sdavids@gmx.de>

Author: sdavids

README.md

@@ -57,6 +57,14 @@ revapi {
 }
 ```
 
+If you want to change the location of the `gradle-revapi` configuration file (default: `.palantir/revapi.yml`), you can do so:
+
+```gradle
+revapi {
+    config = resources.text.fromFile("path/to/revapi.yml")
+}
+```
+
 ### Accepting breaks
 
 Sometimes you may wish to break your API, or feel that the particular API break identified by revapi is acceptable to
@@ -104,7 +112,7 @@ use the
 ./gradle revapiVersionOverride --replacement-version <last-published-version>
 ```
 
-task to use correctly published version instead. This will creare an entry in `.palantir/revapi.yml` of the following
+task to use correctly published version instead. This will creare an entry in the `gradle-revapi` configuration file (default: `.palantir/revapi.yml`) of the following
 format:
 
 ```yml

changelog/@unreleased/pr-650.v2.yml

@@ -0,0 +1,5 @@
+type: feature
+fix:
+  description: add config parameter to RevapiExtension
+  links:
+  - https://github.com/palantir/gradle-revapi/pull/650

src/main/java/com/palantir/gradle/revapi/RevapiExtension.java

@@ -25,13 +25,15 @@
 import org.gradle.api.provider.ListProperty;
 import org.gradle.api.provider.Property;
 import org.gradle.api.provider.Provider;
+import org.gradle.api.resources.TextResource;
 
 @SuppressWarnings("DesignForExtension")
 public class RevapiExtension {
     private final Property<String> oldGroup;
     private final Property<String> oldName;
     private final ListProperty<String> oldVersions;
     private final Provider<GroupAndName> oldGroupAndName;
+    private TextResource config;
 
     public RevapiExtension(Project project) {
         this.oldGroup = project.getObjects().property(String.class);
@@ -75,4 +77,12 @@ GroupNameVersion oldGroupNameVersion() {
     Provider<GroupAndName> oldGroupAndName() {
         return oldGroupAndName;
     }
+
+    public TextResource getConfig() {
+        return config;
+    }
+
+    public void setConfig(TextResource config) {
+        this.config = config;
+    }
 }

src/main/java/com/palantir/gradle/revapi/RevapiPlugin.java

@@ -33,6 +33,7 @@
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.provider.Provider;
+import org.gradle.api.resources.TextResource;
 import org.gradle.api.specs.Spec;
 import org.gradle.api.tasks.TaskProvider;
 import org.gradle.api.tasks.bundling.Jar;
@@ -50,7 +51,7 @@ public void apply(Project project) {
 
         RevapiExtension extension = project.getExtensions().create("revapi", RevapiExtension.class, project);
 
-        ConfigManager configManager = new ConfigManager(configFile(project));
+        ConfigManager configManager = new ConfigManager(configFile(project, extension));
 
         Provider<Optional<OldApi>> maybeOldApi = ResolveOldApi.oldApiProvider(project, extension, configManager);
         Spec<Task> oldApiIsPresent = _task -> maybeOldApi.get().isPresent();
@@ -173,8 +174,12 @@ static Provider<Set<Jar>> allJarTasksIncludingDependencies(Project project, Conf
                         .collect(Collectors.toSet()));
     }
 
-    private static File configFile(Project project) {
-        return new File(project.getRootDir(), ".palantir/revapi.yml");
+    private static File configFile(Project project, RevapiExtension extension) {
+        TextResource config = extension.getConfig();
+        if (config == null) {
+            return new File(project.getRootDir(), ".palantir/revapi.yml");
+        }
+        return config.asFile();
     }
 
     private File junitOutput(Project project) {