From ad83630072b0efaa49c91fd86373e895bd59bfcf Mon Sep 17 00:00:00 2001
From: Jonah Jeleniewski <jjeleniewski@integradev.com.au>
Date: Tue, 8 Oct 2024 12:16:41 +1100
Subject: [PATCH] Fix parsing errors on `implementation` keywords in
 conditional branches

---
 CHANGELOG.md                                  |  4 ++++
 .../au/com/integradev/delphi/antlr/Delphi.g   |  5 +++--
 .../delphi/file/DelphiFileTest.java           | 22 +++++++++++++++++--
 .../delphi/file/SkipImplementation.pas        |  9 ++++++++
 ...SkipImplementationWithDirectiveNesting.pas | 14 ++++++++++++
 5 files changed, 50 insertions(+), 4 deletions(-)
 create mode 100644 delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementation.pas
 create mode 100644 delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementationWithDirectiveNesting.pas

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 15ce12370..f6ea42b89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Parsing errors on `implementation` keywords nested in conditional branches.
+
 ## [1.10.0] - 2024-10-01
 
 ### Added
diff --git a/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g b/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g
index 3024c0c5e..b75d52505 100644
--- a/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g
+++ b/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g
@@ -122,6 +122,7 @@ import au.com.integradev.delphi.antlr.ast.node.*;
 
 package au.com.integradev.delphi.antlr;
 
+import org.apache.commons.lang3.StringUtils;
 }
 
 @lexer::members {
@@ -1503,9 +1504,9 @@ COMMENT                 :  '//' ~('\n'|'\r')*                          {$channel
 
                               if ($text.startsWith(start + "\$")) {
                                 $type = TkCompilerDirective;
-                                if ($text.startsWith(start + "\$endif") || $text.startsWith(start + "\$ifend")) {
+                                if (StringUtils.startsWithIgnoreCase($text, start + "\$endif") || StringUtils.startsWithIgnoreCase($text, start + "\$ifend")) {
                                   --directiveNesting;
-                                } else if ($text.startsWith(start + "\$if")) {
+                                } else if (StringUtils.startsWithIgnoreCase($text, start + "\$if")) {
                                   ++directiveNesting;
                                 }
                               }
diff --git a/delphi-frontend/src/test/java/au/com/integradev/delphi/file/DelphiFileTest.java b/delphi-frontend/src/test/java/au/com/integradev/delphi/file/DelphiFileTest.java
index af9b28311..faee59963 100644
--- a/delphi-frontend/src/test/java/au/com/integradev/delphi/file/DelphiFileTest.java
+++ b/delphi-frontend/src/test/java/au/com/integradev/delphi/file/DelphiFileTest.java
@@ -18,8 +18,7 @@
  */
 package au.com.integradev.delphi.file;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.Assertions.*;
 
 import au.com.integradev.delphi.compiler.Platform;
 import au.com.integradev.delphi.core.Delphi;
@@ -36,6 +35,8 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.sonar.api.batch.fs.InputFile;
 import org.sonar.api.batch.fs.internal.TestInputFileBuilder;
 
@@ -106,4 +107,21 @@ void testByteOrderMarkShouldBeStripped() {
     String firstLine = delphiFile.getSourceCodeFileLines().get(0);
     assertThat(firstLine).doesNotStartWith("\ufeff");
   }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"SkipImplementation.pas", "SkipImplementationWithDirectiveNesting.pas"})
+  void testShouldSkipImplementation(String filename) {
+    File file = DelphiUtils.getResource("/au/com/integradev/delphi/file/" + filename);
+
+    DelphiFileConfig config =
+        DelphiFile.createConfig(
+            StandardCharsets.UTF_8.name(),
+            new DelphiPreprocessorFactory(Platform.WINDOWS),
+            TypeFactoryUtils.defaultFactory(),
+            SearchPath.create(Collections.emptyList()),
+            Collections.emptySet(),
+            true);
+
+    assertThatNoException().isThrownBy(() -> DelphiFile.from(file, config));
+  }
 }
diff --git a/delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementation.pas b/delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementation.pas
new file mode 100644
index 000000000..1d9bddbfd
--- /dev/null
+++ b/delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementation.pas
@@ -0,0 +1,9 @@
+unit SkipImplementation;
+
+interface
+
+implementation
+
+ERROR
+
+end.
diff --git a/delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementationWithDirectiveNesting.pas b/delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementationWithDirectiveNesting.pas
new file mode 100644
index 000000000..cda577630
--- /dev/null
+++ b/delphi-frontend/src/test/resources/au/com/integradev/delphi/file/SkipImplementationWithDirectiveNesting.pas
@@ -0,0 +1,14 @@
+unit SkipImplementationWithDirectiveNesting;
+
+interface
+
+{$If False}
+type
+  TFoo = ERROR class
+  emd;
+implementation
+{$eLsE}
+implementation
+{$endif}
+
+end.