converting ForbiddenPatternsTask to .java (#36194)

* converting ForbiddenPatternsTask to java impl & unit tests

Author: cdschneider

buildSrc/build.gradle

@@ -223,7 +223,7 @@ if (project != rootProject) {
   forbiddenPatterns {
     exclude '**/*.wav'
     // the file that actually defines nocommit
-    exclude '**/ForbiddenPatternsTask.groovy'
+    exclude '**/ForbiddenPatternsTask.java'
   }
 
   namingConventions {

buildSrc/src/main/groovy/org/elasticsearch/gradle/precommit/ForbiddenPatternsTask.groovy

@@ -0,0 +1,161 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.elasticsearch.gradle.precommit;
+
+import org.gradle.api.DefaultTask;
+import org.gradle.api.GradleException;
+import org.gradle.api.InvalidUserDataException;
+import org.gradle.api.file.FileCollection;
+import org.gradle.api.file.FileTree;
+import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.tasks.Input;
+import org.gradle.api.tasks.InputFiles;
+import org.gradle.api.tasks.OutputFile;
+import org.gradle.api.tasks.SkipWhenEmpty;
+import org.gradle.api.tasks.TaskAction;
+import org.gradle.api.tasks.util.PatternFilterable;
+import org.gradle.api.tasks.util.PatternSet;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.AbstractMap;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+/**
+ * Checks for patterns in source files for the project which are forbidden.
+ */
+public class ForbiddenPatternsTask extends DefaultTask {
+
+    /*
+     * A pattern set of which files should be checked.
+     */
+    private final PatternFilterable filesFilter = new PatternSet()
+        // we always include all source files, and exclude what should not be checked
+        .include("**")
+        // exclude known binary extensions
+        .exclude("**/*.gz")
+        .exclude("**/*.ico")
+        .exclude("**/*.jar")
+        .exclude("**/*.zip")
+        .exclude("**/*.jks")
+        .exclude("**/*.crt")
+        .exclude("**/*.png");
+
+    /*
+     * The rules: a map from the rule name, to a rule regex pattern.
+     */
+    private final Map<String, String> patterns = new HashMap<>();
+
+    public ForbiddenPatternsTask() {
+        setDescription("Checks source files for invalid patterns like nocommits or tabs");
+        getInputs().property("excludes", filesFilter.getExcludes());
+        getInputs().property("rules", patterns);
+
+        // add mandatory rules
+        patterns.put("nocommit", "nocommit|NOCOMMIT");
+        patterns.put("nocommit should be all lowercase or all uppercase", "((?i)nocommit)(?<!(nocommit|NOCOMMIT))");
+        patterns.put("tab", "\t");
+    }
+
+    @InputFiles
+    @SkipWhenEmpty
+    public FileCollection files() {
+        return getProject().getConvention().getPlugin(JavaPluginConvention.class).getSourceSets()
+            .stream()
+            .map(sourceSet -> sourceSet.getAllSource().matching(filesFilter))
+            .reduce(FileTree::plus)
+            .orElse(getProject().files().getAsFileTree());
+    }
+
+    @TaskAction
+    public void checkInvalidPatterns() throws IOException {
+        Pattern allPatterns = Pattern.compile("(" + String.join(")|(", getPatterns().values()) + ")");
+        List<String> failures = new ArrayList<>();
+        for (File f : files()) {
+            List<String> lines;
+            try(Stream<String> stream = Files.lines(f.toPath(), StandardCharsets.UTF_8)) {
+                    lines = stream.collect(Collectors.toList());
+            } catch (UncheckedIOException e) {
+                throw new IllegalArgumentException("Failed to read " + f + " as UTF_8", e);
+            }
+            List<Integer> invalidLines = IntStream.range(0, lines.size())
+                .filter(i -> allPatterns.matcher(lines.get(i)).find())
+                .boxed()
+                .collect(Collectors.toList());
+
+            String path = getProject().getRootProject().getProjectDir().toURI().relativize(f.toURI()).toString();
+            failures = invalidLines.stream()
+                .map(l -> new AbstractMap.SimpleEntry<>(l+1, lines.get(l)))
+                .flatMap(kv -> patterns.entrySet().stream()
+                    .filter(p -> Pattern.compile(p.getValue()).matcher(kv.getValue()).find())
+                    .map(p -> "- " + p.getKey() + " on line " + kv.getKey() + " of " + path)
+                )
+                .collect(Collectors.toList());
+        }
+        if (failures.isEmpty() == false) {
+            throw new GradleException("Found invalid patterns:\n" + String.join("\n", failures));
+        }
+
+        File outputMarker = getOutputMarker();
+        outputMarker.getParentFile().mkdirs();
+        Files.write(outputMarker.toPath(), "done".getBytes(StandardCharsets.UTF_8));
+    }
+
+    @OutputFile
+    public File getOutputMarker() {
+        return new File(getProject().getBuildDir(), "markers/" + getName());
+    }
+
+    @Input
+    public Map<String, String> getPatterns() {
+        return Collections.unmodifiableMap(patterns);
+    }
+
+    public void exclude(String... excludes) {
+        filesFilter.exclude(excludes);
+    }
+
+    public void rule(Map<String,String> props) {
+        String name = props.remove("name");
+        if (name == null) {
+            throw new InvalidUserDataException("Missing [name] for invalid pattern rule");
+        }
+        String pattern = props.remove("pattern");
+        if (pattern == null) {
+            throw new InvalidUserDataException("Missing [pattern] for invalid pattern rule");
+        }
+        if (props.isEmpty() == false) {
+            throw new InvalidUserDataException("Unknown arguments for ForbiddenPatterns rule mapping: "
+                + props.keySet().toString());
+        }
+        // TODO: fail if pattern contains a newline, it won't work (currently)
+        patterns.put(name, pattern);
+    }
+}