Merge pull request #2 from openrewrite/timer_to_observation

Timer to Observation

src/main/java/org/openrewrite/micrometer/TimerToObservation.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2023 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.micrometer;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.internal.StringUtils;
+import org.openrewrite.java.*;
+import org.openrewrite.java.search.UsesMethod;
+import org.openrewrite.java.tree.Expression;
+import org.openrewrite.java.tree.J;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TimerToObservation extends Recipe {
+    private static final String TIMER = "io.micrometer.core.instrument.Timer";
+    private static final String OBSERVATION = "io.micrometer.observation.Observation";
+
+    @Override
+    public String getDisplayName() {
+        return "Convert Micrometer Timer to Observations";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Convert Micrometer Timer to Observations.";
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        return Preconditions.check(
+                Preconditions.and(
+                        Preconditions.or(
+                                new UsesMethod<>(TIMER + " record*(..)", false),
+                                new UsesMethod<>(TIMER + " wrap(..)", false)
+                        ),
+                        Preconditions.and(
+                                Preconditions.not(new UsesMethod<>(TIMER + " record(java.time.Duration)", false)),
+                                Preconditions.not(new UsesMethod<>(TIMER + " record(long, java.util.concurrent.TimeUnit)", false))
+                        )
+                ),
+                new JavaIsoVisitor<ExecutionContext>() {
+                    private final MethodMatcher builderMatcher = new MethodMatcher(OBSERVATION + " builder(String)");
+                    private final MethodMatcher registerMatcher = new MethodMatcher(TIMER + ".Builder register(io.micrometer.observation.ObservationRegistry)");
+                    private final MethodMatcher tagMatcher = new MethodMatcher(TIMER + ".Builder tag(String, String)");
+                    private final MethodMatcher tagsMatcher = new MethodMatcher(TIMER + ".Builder tags(..)");
+                    private final MethodMatcher tagsIterableMatcher = new MethodMatcher(TIMER + ".Builder tags(Iterable)");
+
+                    private final ChangeType changeTypeRegistry = new ChangeType("io.micrometer.core.instrument.MeterRegistry", "io.micrometer.observation.ObservationRegistry", null);
+                    private final ChangeType changeTypeTimer = new ChangeType("io.micrometer.core.instrument.Timer","io.micrometer.observation.Observation", null);
+                    private final ChangeMethodName changeRecord = new ChangeMethodName(OBSERVATION + " record*(..)", "observe", null, null);
+
+                    @Override
+                    public J.CompilationUnit visitCompilationUnit(J.CompilationUnit compilationUnit, ExecutionContext executionContext) {
+                        J.CompilationUnit cu = compilationUnit;
+                        cu = (J.CompilationUnit) changeTypeRegistry.getVisitor().visit(cu, executionContext);
+                        cu = (J.CompilationUnit) changeTypeTimer.getVisitor().visit(cu, executionContext);
+                        cu = (J.CompilationUnit) changeRecord.getVisitor().visit(cu, executionContext);
+                        assert cu != null;
+                        return super.visitCompilationUnit(cu, executionContext);
+                    }
+
+                    @Override
+                    public J.MethodInvocation visitMethodInvocation(J.MethodInvocation mi, ExecutionContext executionContext) {
+                        if (registerMatcher.matches(mi)) {
+                            Expression timerName = null;
+                            Expression registry = mi.getArguments().get(0);
+
+                            List<String> builder = new ArrayList<>();
+                            List<Expression> parameters = new ArrayList<>();
+
+                            Expression maybeBuilder = mi.getSelect();
+                            while (maybeBuilder instanceof J.MethodInvocation) {
+                                J.MethodInvocation builderMethod = (J.MethodInvocation) maybeBuilder;
+                                if (builderMatcher.matches(maybeBuilder)) {
+                                    timerName = builderMethod.getArguments().get(0);
+                                }
+                                else if (tagMatcher.matches(maybeBuilder)) {
+                                    builder.add("\n.highCardinalityKeyValue(#{any(String)}, #{any(String)})");
+                                    parameters.add(builderMethod.getArguments().get(0));
+                                    parameters.add(builderMethod.getArguments().get(1));
+                                }
+                                else if (tagsIterableMatcher.matches(maybeBuilder)) {
+                                    builder.add("\n.highCardinalityKeyValues(KeyValues.of(#{any(Iterable)}, Tag::getKey, Tag::getValue))");
+                                    parameters.addAll(builderMethod.getArguments());
+                                    maybeAddImport("io.micrometer.common.KeyValues");
+                                    maybeAddImport("io.micrometer.core.instrument.Tag");
+                                }
+                                else if (tagsMatcher.matches(maybeBuilder)) {
+                                    String args = StringUtils.repeat("#{any(String)},", builderMethod.getArguments().size());
+                                    args = args.substring(0, args.length() - 1);
+                                    builder.add("\n.highCardinalityKeyValues(KeyValues.of(" + args + "))");
+                                    parameters.addAll(builderMethod.getArguments());
+                                    maybeAddImport("io.micrometer.common.KeyValues");
+                                }
+                                maybeBuilder = ((J.MethodInvocation) maybeBuilder).getSelect();
+                            }
+                            if (timerName != null) {
+                                parameters.add(0, timerName);
+                                parameters.add(1, registry);
+
+                                maybeAddImport("io.micrometer.observation.Observation");
+                                maybeRemoveImport("io.micrometer.core.instrument.Timer");
+
+                                JavaTemplate template = JavaTemplate
+                                        .builder("Observation.createNotStarted(#{any(java.lang.String)}, #{any()})"
+                                                + String.join("", builder))
+                                        .contextSensitive()
+                                        .javaParser(JavaParser.fromJavaVersion()
+                                                .classpathFromResources(executionContext, "micrometer-observation", "micrometer-commons", "micrometer-core"))
+                                        .imports("io.micrometer.observation.Observation")
+                                        .imports("io.micrometer.common.KeyValues")
+                                        .imports("io.micrometer.core.instrument.Tag")
+                                        .build();
+
+                                mi = autoFormat(
+                                        template.apply(updateCursor(mi), mi.getCoordinates().replace(), parameters.toArray()),
+                                        executionContext
+                                );
+                            }
+                        }
+                        return super.visitMethodInvocation(mi, executionContext);
+                    }
+
+                });
+    }
+}

src/main/java/org/openrewrite/micrometer/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2023 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.
+ */
+@NonNullApi @NonNullFields
+package org.openrewrite.micrometer;
+
+import org.openrewrite.internal.lang.NonNullApi;
+import org.openrewrite.internal.lang.NonNullFields;