fix(PositionBuilder): fix lambda parameters position

src/main/java/spoon/support/compiler/jdt/PositionBuilder.java

@@ -224,8 +224,8 @@ SourcePosition buildPositionCtElement(CtElement e, ASTNode node) {
 
 			// Handle lambda parameters without explicit type
 			if (variableDeclaration instanceof Argument && variableDeclaration.type == null) {
-				declarationSourceStart = findPrevNonWhitespace(contents, 0, declarationSourceStart - 1);
-				declarationSourceEnd = findNextNonWhitespace(contents, contents.length - 1, declarationSourceEnd + 1);
+				declarationSourceStart = findPrevNonWhitespace(contents, 0, declarationSourceStart);
+				declarationSourceEnd = findNextNonWhitespace(contents, contents.length - 1, declarationSourceEnd);
 			}
 
 			if (modifiersSourceStart <= 0) {

src/test/java/spoon/test/position/PositionTest.java

@@ -70,8 +70,7 @@
 import spoon.support.compiler.VirtualFile;
 import spoon.support.reflect.CtExtendedModifier;
 import spoon.test.comment.testclasses.BlockComment;
-import spoon.test.comment.testclasses.Comment1;
-import spoon.test.position.testclasses.AnnonymousClassNewIface;
+import spoon.test.comment.testclasses.Comment1;import spoon.test.position.testclasses.AnnonymousClassNewIface;
 import spoon.test.position.testclasses.ArrayArgParameter;
 import spoon.test.position.testclasses.CatchPosition;
 import spoon.test.position.testclasses.CompilationUnitComments;
@@ -88,6 +87,7 @@
 import spoon.test.position.testclasses.FooGeneric;
 import spoon.test.position.testclasses.FooInterface;
 import spoon.test.position.testclasses.FooLabel;
+import spoon.test.position.testclasses.FooLambda;
 import spoon.test.position.testclasses.FooMethod;
 import spoon.test.position.testclasses.FooStatement;
 import spoon.test.position.testclasses.FooSwitch;
@@ -97,6 +97,7 @@
 import spoon.test.position.testclasses.PositionTry;
 import spoon.test.position.testclasses.SomeEnum;
 import spoon.test.position.testclasses.TypeParameter;
+import spoon.test.position.testclasses.MoreLambda;
 import spoon.test.query_function.testclasses.VariableReferencesModelTest;
 import spoon.testing.utils.ModelUtils;
 
@@ -1396,4 +1397,34 @@ public void testLinePositionOkWithOneLineClassCode() {
 		assertTrue("Some Spoon elements have an invalid line position",
 			listOfBadPositionElements.stream().allMatch(elt -> elt.getPosition().getLine() == 1));
 	}
+
+	@Test
+	public void testLambdaParameterPosition() {
+		// contract: position of lambda parameter is correct
+		final Factory build = build(new File("src/test/java/spoon/test/position/testclasses/FooLambda.java"));
+		final CtType<?> foo = build.Type().get(FooLambda.class);
+
+		String classContent = getClassContent(foo);
+
+		CtReturn<?> retStmt = (CtReturn<?>) foo.getMethodsByName("m").get(0).getBody().getStatement(0);
+		CtLambda<?> lambdaExpr = (CtLambda<?>) retStmt.getReturnedExpression();
+		CtParameter<?> param = lambdaExpr.getParameters().get(0);
+		assertEquals("i", contentAtPosition(classContent, param.getPosition()));
+	}
+
+	@Test
+	public void testLambdaParameterPosition1() {
+		// contract: position of lambda parameter is correct
+		final Factory build = build(new File("src/test/java/spoon/test/position/testclasses/MoreLambda.java"));
+		final CtType<?> foo = build.Type().get(MoreLambda.class);
+
+		String classContent = getClassContent(foo);
+
+		List<CtLambda>  lambdas = foo.getElements(new TypeFilter(CtLambda.class));
+		lambdas.stream().forEach(
+				l -> l.getParameters().stream().forEach(
+						p -> assertEquals(((CtParameter) p).getSimpleName(), contentAtPosition(classContent, ((CtParameter) p).getPosition()))
+				)
+		);
+	}
 }

src/test/java/spoon/test/position/testclasses/MoreLambda.java

@@ -0,0 +1,43 @@
+package spoon.test.position.testclasses;
+
+import java.util.function.BiPredicate;
+import java.util.function.Predicate;
+
+public class MoreLambda {
+
+    public static Predicate<Integer> m0() {
+        return integer -> integer.compareTo(7) > 0;
+    }
+
+    public static Predicate<Integer> m1() {
+        return in -> in.compareTo(7) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m2() {
+        return (i,j) -> i.compareTo(j) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m3() {
+        return (i ,j) -> i.compareTo(j) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m4() {
+        return (i , j) -> i.compareTo(j) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m5() {
+        return (in , jn) -> in.compareTo(jn) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m6() {
+        return (integer , jnteger) -> integer.compareTo(jnteger) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m7() {
+        return (in, jn) -> in.compareTo(jn) > 0;
+    }
+
+    public static BiPredicate<Integer, Integer> m8() {
+        return ( integer ,jnteger) -> integer.compareTo(jnteger) > 0;
+    }
+}