Recipe to print out git provenance (#2640)

rewrite-core/src/main/java/org/openrewrite/ShowGitProvenance.java

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+/*
+ * Copyright 2022 the original author or authors.
+ * <p>
+ * Licensed 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
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.openrewrite;
+
+import org.openrewrite.internal.ListUtils;
+import org.openrewrite.marker.GitProvenance;
+import org.openrewrite.marker.Markup;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class ShowGitProvenance extends Recipe {
+
+    @Override
+    public String getDisplayName() {
+        return "Show Git source control metadata";
+    }
+
+    @Override
+    public String getDescription() {
+        return "List out the contents of each unique `GitProvenance` marker in the set of source files. " +
+               "When everything is working correctly, exactly one such marker should be printed as all source files are " +
+               "expected to come from the same repository / branch / commit ID.";
+    }
+
+    @Override
+    protected List<SourceFile> visit(List<SourceFile> before, ExecutionContext ctx) {
+        Set<GitProvenance> provenances = new HashSet<>();
+
+        return ListUtils.map(before, sourceFile -> {
+            GitProvenance provenance = sourceFile.getMarkers().findFirst(GitProvenance.class).orElse(null);
+            if (provenance == null || !provenances.add(provenance)) {
+                return sourceFile;
+            }
+            return Markup.info(sourceFile, String.format("GitProvenance:\n" +
+                                                         "    origin: %s\n" +
+                                                         "    branch: %s\n" +
+                                                         "    changeset: %s\n" +
+                                                         "    autocrlf: %s\n" +
+                                                         "    eol: %s",
+                    provenance.getOrigin(),
+                    provenance.getBranch(),
+                    provenance.getChange(),
+                    provenance.getAutocrlf() != null ? provenance.getAutocrlf().toString() : "null",
+                    provenance.getEol() != null ? provenance.getEol().toString() : "null"));
+        });
+    }
+}

rewrite-core/src/test/java/org/openrewrite/ShowGitProvenanceTest.java

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+/*
+ * Copyright 2022 the original author or authors.
+ * <p>
+ * Licensed 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
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.openrewrite;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.marker.GitProvenance;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.marker.GitProvenance.AutoCRLF.False;
+import static org.openrewrite.marker.GitProvenance.EOL.Native;
+import static org.openrewrite.test.SourceSpecs.text;
+
+class ShowGitProvenanceTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new ShowGitProvenance());
+    }
+
+    @Test
+    void showGitProvenance() {
+        rewriteRun(
+          text("Hello, World!", """
+              ~~(GitProvenance:
+                  origin: https://github.com/moderneinc/moderne-scm
+                  branch: main
+                  changeset: 1234567
+                  autocrlf: False
+                  eol: Native)~~>Hello, World!""",
+            spec -> spec.markers(new GitProvenance(Tree.randomId(), "https://github.com/moderneinc/moderne-scm", "main", "1234567", False, Native))
+          )
+        );
+    }
+}