. t find method's line numbers using java parser

approvaltests-tests/pom.xml

@@ -130,6 +130,11 @@
             <artifactId>jakarta.mail</artifactId>
             <version>2.0.1</version>
         </dependency>
+        <dependency>
+            <groupId>com.github.javaparser</groupId>
+            <artifactId>javaparser-core</artifactId>
+            <version>3.23.1</version>
+        </dependency>
     </dependencies>
 
     <build>

approvaltests-tests/src/test/java/org/approvaltests/ParsingFilesTest.java

@@ -0,0 +1,47 @@
+package org.approvaltests;
+
+import com.github.javaparser.Range;
+import com.github.javaparser.ast.CompilationUnit;
+import com.github.javaparser.utils.SourceRoot;
+import com.spun.util.StringUtils;
+import org.approvaltests.core.Options;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.lang.reflect.Method;
+import java.nio.file.Paths;
+
+public class ParsingFilesTest
+{
+  @Test
+  public void getLineNumberOfThisMethod() throws Exception
+  {
+    var expected = """
+      (line 5,col 3)-(line 7,col 3)
+      """;
+    Method method = XmlApprovals.class.getMethod("verify", String.class);
+    Range r = getMethodLines(method);
+    Approvals.verify(r, new Options().inline(expected));
+  }
+  private Range getMethodLines(Method method)
+  {
+    CompilationUnit compilationUnit = parseJavaFile(method);
+    return compilationUnit.getClassByName("XmlApprovals").get().getMember(0).getRange().get();
+  }
+  private CompilationUnit parseJavaFile(Method method)
+  {
+    File filePath = getSourceFile(method);
+    String baseDir = StringUtils.removeFromEnd(System.getProperty("user.dir"), "-tests") + "/src/main/java/";
+    SourceRoot sourceRoot = new SourceRoot(Paths.get(baseDir));
+    String packageName = method.getDeclaringClass().getPackageName();
+    String name = filePath.getName();
+    return sourceRoot.parse(packageName, name);
+  }
+  private File getSourceFile(Method method)
+  {
+    String baseDir = StringUtils.removeFromEnd(System.getProperty("user.dir"), "-tests");
+    String className = method.getDeclaringClass().getName();
+    String relativePath = "src/main/java/" + className.replace('.', '/') + ".java";
+    return new File(baseDir, relativePath);
+  }
+}

approvaltests-util/src/main/java/com/spun/util/StringUtils.java

@@ -623,4 +623,12 @@ public static String padLeft(String contents, int targetLength)
     }
     return contents;
   }
+  public static String removeFromEnd(String contents, String text)
+  {
+    return removeFromEnd(contents, text.length());
+  }
+  public static String removeFromEnd(String contents, int length)
+  {
+    return contents.substring(0, contents.length() - length);
+  }
 }

approvaltests/src/main/java/org/approvaltests/XmlApprovals.java

@@ -0,0 +1,8 @@
+package org.approvaltests;
+
+public class XmlApprovals
+{
+  public static void verify(String xml)
+  {
+  }
+}