Make access transformer spec hash code consistent

Fixes #119.

src/main/java/net/fabricmc/loom/configuration/accesstransformer/AccessTransformerEntry.java

@@ -0,0 +1,65 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2023 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.configuration.accesstransformer;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import net.fabricmc.loom.util.Constants;
+import net.fabricmc.loom.util.fmj.FabricModJson;
+
+public interface AccessTransformerEntry {
+	Reader openReader() throws IOException;
+
+	record Standalone(Path path, String hash) implements AccessTransformerEntry {
+		@Override
+		public Reader openReader() throws IOException {
+			return Files.newBufferedReader(path);
+		}
+
+		@Override
+		public String toString() {
+			return path.toString();
+		}
+	}
+
+	record Mod(FabricModJson fmj, String hash) implements AccessTransformerEntry {
+		@Override
+		public Reader openReader() throws IOException {
+			final byte[] bytes = fmj.getSource().read(Constants.Forge.ACCESS_TRANSFORMER_PATH);
+			return new InputStreamReader(new ByteArrayInputStream(bytes), StandardCharsets.UTF_8);
+		}
+
+		@Override
+		public String toString() {
+			return fmj.toString();
+		}
+	}
+}

src/main/java/net/fabricmc/loom/configuration/accesstransformer/AccessTransformerJarProcessor.java

@@ -27,6 +27,7 @@ package net.fabricmc.loom.configuration.accesstransformer;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.Reader;
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
@@ -43,7 +44,6 @@ import dev.architectury.loom.util.TempFiles;
 import org.cadixdev.at.AccessTransformSet;
 import org.cadixdev.at.io.AccessTransformFormats;
 import org.gradle.api.Project;
-import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.logging.Logger;
 import org.gradle.api.logging.Logging;
@@ -65,11 +65,10 @@ public class AccessTransformerJarProcessor implements MinecraftJarProcessor<Acce
 	private static final Logger LOGGER = Logging.getLogger(AccessTransformerJarProcessor.class);
 	private final String name;
 	private final Project project;
-	private final ConfigurableFileCollection localAccessTransformers;
-	private final TempFiles tempFiles = new TempFiles();
+	private final Iterable<File> localAccessTransformers;
 
 	@Inject
-	public AccessTransformerJarProcessor(String name, Project project, ConfigurableFileCollection localAccessTransformers) {
+	public AccessTransformerJarProcessor(String name, Project project, Iterable<File> localAccessTransformers) {
 		this.name = name;
 		this.project = project;
 		this.localAccessTransformers = localAccessTransformers;
@@ -89,7 +88,7 @@ public class AccessTransformerJarProcessor implements MinecraftJarProcessor<Acce
 				throw new UncheckedIOException("Could not compute AT hash", e);
 			}
 
-			entries.add(new AccessTransformerEntry(atPath, hash));
+			entries.add(new AccessTransformerEntry.Standalone(atPath, hash));
 		}
 
 		for (FabricModJson localMod : context.localMods()) {
@@ -104,16 +103,7 @@ public class AccessTransformerJarProcessor implements MinecraftJarProcessor<Acce
 			}
 
 			final String hash = Hashing.sha256().hashBytes(bytes).toString();
-			final Path atPath;
-
-			try {
-				atPath = tempFiles.file("accesstransformer", ".cfg");
-				Files.write(atPath, bytes);
-			} catch (IOException e) {
-				throw ExceptionUtil.createDescriptiveWrapper(UncheckedIOException::new, "Could not create temporary AT file", e);
-			}
-
-			entries.add(new AccessTransformerEntry(atPath, hash));
+			entries.add(new AccessTransformerEntry.Mod(localMod, hash));
 		}
 
 		return !entries.isEmpty() ? new Spec(entries) : null;
@@ -121,11 +111,11 @@ public class AccessTransformerJarProcessor implements MinecraftJarProcessor<Acce
 
 	@Override
 	public void processJar(Path jar, Spec spec, ProcessorContext context) throws IOException {
-		try (tempFiles) {
+		try (var tempFiles = new TempFiles()) {
 			LOGGER.lifecycle(":applying project access transformers");
 			final Path tempInput = tempFiles.file("input", ".jar");
 			Files.copy(jar, tempInput, StandardCopyOption.REPLACE_EXISTING);
-			final Path atPath = mergeAndRemapAccessTransformers(context, spec.accessTransformers());
+			final Path atPath = mergeAndRemapAccessTransformers(context, spec.accessTransformers(), tempFiles);
 
 			executeAt(project, tempInput, jar, args -> {
 				args.add("--atFile");
@@ -136,14 +126,14 @@ public class AccessTransformerJarProcessor implements MinecraftJarProcessor<Acce
 		}
 	}
 
-	private Path mergeAndRemapAccessTransformers(ProcessorContext context, List<AccessTransformerEntry> accessTransformers) throws IOException {
+	private Path mergeAndRemapAccessTransformers(ProcessorContext context, List<AccessTransformerEntry> accessTransformers, TempFiles tempFiles) throws IOException {
 		AccessTransformSet accessTransformSet = AccessTransformSet.create();
 
 		for (AccessTransformerEntry entry : accessTransformers) {
-			try {
-				accessTransformSet.merge(AccessTransformFormats.FML.read(entry.path()));
+			try (Reader reader = entry.openReader()) {
+				accessTransformSet.merge(AccessTransformFormats.FML.read(reader));
 			} catch (IOException e) {
-				throw new IOException("Could not read access transformer " + entry.path(), e);
+				throw new IOException("Could not read access transformer " + entry, e);
 			}
 		}
 
@@ -193,7 +183,4 @@ public class AccessTransformerJarProcessor implements MinecraftJarProcessor<Acce
 
 	public record Spec(List<AccessTransformerEntry> accessTransformers) implements MinecraftJarProcessor.Spec {
 	}
-
-	private record AccessTransformerEntry(Path path, String hash) {
-	}
 }

src/test/groovy/net/fabricmc/loom/test/unit/forge/AccessTransformerJarProcessorTest.groovy

@@ -0,0 +1,61 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2023 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.test.unit.forge
+
+import net.fabricmc.loom.api.processor.SpecContext
+import net.fabricmc.loom.configuration.accesstransformer.AccessTransformerJarProcessor
+import net.fabricmc.loom.util.fmj.FabricModJsonFactory
+import org.gradle.api.Project
+import spock.lang.Specification
+import spock.lang.TempDir
+
+import java.nio.file.Files
+import java.nio.file.Path
+
+class AccessTransformerJarProcessorTest extends Specification {
+    private static final String TEST_ACCESS_TRANSFORMER = 'public-f net.minecraft.world.level.block.IronBarsBlock m_54217_(Lnet/minecraft/world/level/block/state/BlockState;Z)Z'
+
+    @TempDir
+    Path tempDir
+
+    def "consistent spec hash"() {
+        given:
+            // Set up mods.toml and access transformer
+            def metaInf = tempDir.resolve('META-INF')
+            Files.createDirectory(metaInf)
+            metaInf.resolve('accesstransformer.cfg').text = TEST_ACCESS_TRANSFORMER
+            metaInf.resolve('mods.toml').text = '[[mods]]\nmodId="hello"'
+
+            // Create processor and context
+            def processor = new AccessTransformerJarProcessor('at', Mock(Project), [])
+            def modJson = FabricModJsonFactory.createFromDirectory(tempDir)
+            def context = Mock(SpecContext)
+            context.localMods() >> [modJson]
+        when:
+            def spec = processor.buildSpec(context)
+        then:
+            spec.hashCode() == 1575235360
+    }
+}