Remove regex pattern from ParsingUtils

micrometer-docs-generator/src/main/java/io/micrometer/docs/commons/ParsingUtils.java

@@ -20,8 +20,6 @@
 import java.util.List;
 import java.util.Set;
 import java.util.TreeSet;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 import io.micrometer.common.docs.KeyName;
 import io.micrometer.common.lang.Nullable;
@@ -102,14 +100,21 @@ public static Set<String> readEnumClassNames(MethodSource<?> methodSource) {
         MethodInvocation methodInvocation = (MethodInvocation) expression;
 
         if ("merge".equals(methodInvocation.getName().getIdentifier())) {
-            // TODO: There must be a better way to do this...
             // KeyName.merge(TestSpanTags.values(),AsyncSpanTags.values())
-            String invocationString = methodInvocation.toString();
-            Matcher matcher = Pattern.compile("([a-zA-Z]+.values)").matcher(invocationString);
             Set<String> classNames = new TreeSet<>();
-            while (matcher.find()) {
-                String className = matcher.group(1).split("\\.")[0];
-                classNames.add(className);
+
+            // Traverse arguments of the "merge" method
+            for (Object argument : methodInvocation.arguments()) {
+                if (argument instanceof MethodInvocation) {
+                    MethodInvocation argInvocation = (MethodInvocation) argument;
+
+                    // Ensure the method is ".values()" and extract its class name
+                    if ("values".equals(argInvocation.getName().getIdentifier())
+                            && argInvocation.getExpression() != null) {
+                        Expression className = argInvocation.getExpression();
+                        classNames.add(className.toString());
+                    }
+                }
             }
             return classNames;
         }

micrometer-docs-generator/src/test/java/io/micrometer/docs/commons/ParsingUtilsReadEnumClassNamesTests.java

@@ -19,6 +19,8 @@
 import java.util.Set;
 
 import io.micrometer.common.docs.KeyName;
+import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.docs.MeterDocumentation;
 import io.micrometer.docs.RoasterTestUtils;
 import org.jboss.forge.roaster.model.source.JavaClassSource;
 import org.jboss.forge.roaster.model.source.MethodSource;
@@ -49,6 +51,15 @@ void readMergeEnumClassName() {
         assertThat(result).containsExactlyInAnyOrder("FooKeyName", "BarKeyName", "BazKeyName");
     }
 
+    @Test
+    void readNestedEnumClassName() {
+        JavaClassSource javaSource = RoasterTestUtils.readJavaClass(ParsingUtilsReadEnumClassNamesTests.class);
+        MethodSource<?> methodSource = ((JavaClassSource) javaSource.getNestedType("MyClass")).getMethod("mergeNested");
+        Set<String> result = ParsingUtils.readEnumClassNames(methodSource);
+        assertThat(result).containsExactlyInAnyOrder("FooMeterDocumentation.NestedFooKeyName",
+                "FooMeterDocumentation.NestedBarKeyName");
+    }
+
     static class MyClass {
 
         Enum<?>[] simple() {
@@ -59,6 +70,11 @@ KeyName[] merge() {
             return KeyName.merge(FooKeyName.values(), BarKeyName.values(), BazKeyName.values());
         }
 
+        KeyName[] mergeNested() {
+            return KeyName.merge(FooMeterDocumentation.NestedFooKeyName.values(),
+                    FooMeterDocumentation.NestedBarKeyName.values());
+        }
+
     }
 
     enum FooKeyName implements KeyName {
@@ -94,4 +110,42 @@ public String asString() {
 
     }
 
+    enum FooMeterDocumentation implements MeterDocumentation {
+
+        FOO {
+            @Override
+            public String getName() {
+                return "foo";
+            }
+
+            @Override
+            public Meter.Type getType() {
+                return Meter.Type.COUNTER;
+            }
+        };
+
+        enum NestedFooKeyName implements KeyName {
+
+            NESTED_FOO {
+                @Override
+                public String asString() {
+                    return "nested.foo";
+                }
+            }
+
+        }
+
+        enum NestedBarKeyName implements KeyName {
+
+            NESTED_BAR {
+                @Override
+                public String asString() {
+                    return "nested.bar";
+                }
+            }
+
+        }
+
+    }
+
 }