Support configuration of P2 mirrors (#1635 fixes #1629)

Author: nedtwigg

Diff for: CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Added
+* Support configuration of mirrors for P2 repositories in `EquoBasedStepBuilder` ([#1629](https://github.com/diffplug/spotless/issues/1629)).
 ### Changes
 * **POTENTIALLY BREAKING** Converted `googleJavaFormat` to a compile-only dependency and drop support for versions < `1.8`. ([#1630](https://github.com/diffplug/spotless/pull/1630))
 * Bump default `googleJavaFormat` version `1.15.0` -> `1.16.0`. ([#1630](https://github.com/diffplug/spotless/pull/1630))

Diff for: lib-extra/src/main/java/com/diffplug/spotless/extra/EquoBasedStepBuilder.java

@@ -19,6 +19,7 @@
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 
 import com.diffplug.spotless.FileSignature;
@@ -43,6 +44,7 @@ public abstract class EquoBasedStepBuilder {
 	private final ThrowingEx.Function<State, FormatterFunc> stateToFormatter;
 	private String formatterVersion;
 	private Iterable<File> settingsFiles = new ArrayList<>();
+	private Map<String, String> p2Mirrors = Map.of();
 
 	/** Initialize valid default configuration, taking latest version */
 	public EquoBasedStepBuilder(String formatterName, Provisioner mavenProvisioner, ThrowingEx.Function<State, FormatterFunc> stateToFormatter) {
@@ -59,6 +61,10 @@ public void setPreferences(Iterable<File> settingsFiles) {
 		this.settingsFiles = settingsFiles;
 	}
 
+	public void setP2Mirrors(Map<String, String> p2Mirrors) {
+		this.p2Mirrors = Map.copyOf(p2Mirrors);
+	}
+
 	/** Returns the FormatterStep (whose state will be calculated lazily). */
 	public FormatterStep build() {
 		return FormatterStep.createLazy(formatterName, this::get, stateToFormatter);
@@ -85,10 +91,10 @@ protected void addPlatformRepo(P2Model model, String version) {
 
 	/** Creates the state of the configuration. */
 	EquoBasedStepBuilder.State get() throws Exception {
-		var query = model(formatterVersion).query(P2ClientCache.PREFER_OFFLINE, P2QueryCache.ALLOW);
+		var query = createModelWithMirrors().query(P2ClientCache.PREFER_OFFLINE, P2QueryCache.ALLOW);
 		var classpath = new ArrayList<File>();
 		var mavenDeps = new ArrayList<String>();
-		mavenDeps.add("dev.equo.ide:solstice:1.0.0");
+		mavenDeps.add("dev.equo.ide:solstice:1.0.3");
 		mavenDeps.add("com.diffplug.durian:durian-swt.os:4.1.1");
 		mavenDeps.addAll(query.getJarsOnMavenCentral());
 		classpath.addAll(mavenProvisioner.provisionWithTransitives(false, mavenDeps));
@@ -100,6 +106,29 @@ EquoBasedStepBuilder.State get() throws Exception {
 		return new State(formatterVersion, jarState, FileSignature.signAsList(settingsFiles));
 	}
 
+	private P2Model createModelWithMirrors() {
+		P2Model model = model(formatterVersion);
+		if (p2Mirrors.isEmpty()) {
+			return model;
+		}
+
+		ArrayList<String> p2Repos = new ArrayList<>(model.getP2repo());
+		p2Repos.replaceAll(url -> {
+			for (Map.Entry<String, String> mirror : p2Mirrors.entrySet()) {
+				String prefix = mirror.getKey();
+				if (url.startsWith(prefix)) {
+					return mirror.getValue() + url.substring(prefix.length());
+				}
+			}
+
+			throw new IllegalStateException("no mirror configured for P2 repository: " + url);
+		});
+
+		model.getP2repo().clear();
+		model.getP2repo().addAll(p2Repos);
+		return model;
+	}
+
 	/**
 	 * State of Eclipse configuration items, providing functionality to derived information
 	 * based on the state.

Diff for: plugin-gradle/CHANGES.md

@@ -3,6 +3,17 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `3.27.0`).
 
 ## [Unreleased]
+### Added
+* Support configuration of mirrors for P2 repositories ([#1629](https://github.com/diffplug/spotless/issues/1629)):
+  ```
+  spotless {
+    java {
+      eclipse().withP2Mirrors(['https://download.eclipse.org/', 'https://some.internal.mirror/eclipse'])
+    }
+  }
+  ```
+  Mirrors are selected by prefix match, for example `https://download.eclipse.org/eclipse/updates/4.26/` will be redirected to `https://some.internal.mirror/eclipse/eclipse/updates/4.26/`.
+  The same configuration exists for `greclipse` and `eclipseCdt`.
 ### Changes
 * **POTENTIALLY BREAKING** Drop support for `googleJavaFormat` versions < `1.8`. ([#1630](https://github.com/diffplug/spotless/pull/1630))
 * Bump default `googleJavaFormat` version `1.15.0` -> `1.16.0`. ([#1630](https://github.com/diffplug/spotless/pull/1630))

Diff for: plugin-gradle/src/main/java/com/diffplug/gradle/spotless/CppExtension.java

@@ -17,6 +17,8 @@
 
 import static com.diffplug.gradle.spotless.PluginGradlePreconditions.requireElementsNonNull;
 
+import java.util.Map;
+
 import javax.inject.Inject;
 
 import org.gradle.api.Project;
@@ -56,6 +58,12 @@ public void configFile(Object... configFiles) {
 			builder.setPreferences(project.files(configFiles).getFiles());
 			replaceStep(builder.build());
 		}
+
+		public EclipseConfig withP2Mirrors(Map<String, String> mirrors) {
+			builder.setP2Mirrors(mirrors);
+			replaceStep(builder.build());
+			return this;
+		}
 	}
 
 	@Override

Diff for: plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GroovyExtension.java

@@ -17,6 +17,7 @@
 
 import static com.diffplug.gradle.spotless.PluginGradlePreconditions.requireElementsNonNull;
 
+import java.util.Map;
 import java.util.Objects;
 
 import javax.inject.Inject;
@@ -99,6 +100,12 @@ public void configFile(Object... configFiles) {
 			builder.setPreferences(project.files(configFiles).getFiles());
 			extension.replaceStep(builder.build());
 		}
+
+		public GrEclipseConfig withP2Mirrors(Map<String, String> mirrors) {
+			builder.setP2Mirrors(mirrors);
+			extension.replaceStep(builder.build());
+			return this;
+		}
 	}
 
 	/** If the user hasn't specified the files yet, we'll assume he/she means all of the groovy files. */

Diff for: plugin-gradle/src/main/java/com/diffplug/gradle/spotless/JavaExtension.java

@@ -21,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 
 import javax.inject.Inject;
@@ -232,6 +233,12 @@ public void configFile(Object... configFiles) {
 			replaceStep(builder.build());
 		}
 
+		public EclipseConfig withP2Mirrors(Map<String, String> mirrors) {
+			builder.setP2Mirrors(mirrors);
+			replaceStep(builder.build());
+			return this;
+		}
+
 	}
 
 	/** Removes newlines between type annotations and types. */