From 5d8dcf019d5dd6343454f966ddccea224b0033b0 Mon Sep 17 00:00:00 2001
From: Marco Hunsicker <antlr4@hunsicker.de>
Date: Mon, 14 Nov 2016 00:37:41 +0100
Subject: [PATCH] Adds unit tests for the dependency management

---
 antlr4-maven-plugin/pom.xml                   |  66 +++-
 .../org/antlr/mojo/antlr4/Antlr4MojoTest.java | 319 ++++++++++++++++++
 .../src/test/projects/importTokens/pom.xml    |  27 ++
 .../main/antlr4/imports/SimpleLexer.tokens    |   3 +
 .../src/main/antlr4/test/SimpleParser.g4      |   8 +
 .../src/test/projects/importsCustom/pom.xml   |  42 +++
 .../importsCustom/src/main/antlr4/Hello.g4    |   4 +
 .../src/main/antlr4/TestLexer.g4              |   6 +
 .../src/main/antlr4/TestParser.g4             |   5 +
 .../src/main/antlr4/imports/TestBaseLexer.g4  |  16 +
 .../src/test/projects/importsStandard/pom.xml |  27 ++
 .../src/main/antlr4/imports/TestBaseLexer.g4  |  16 +
 .../src/main/antlr4/test/Hello.g4             |   4 +
 .../src/main/antlr4/test/TestLexer.g4         |   6 +
 .../src/main/antlr4/test/TestParser.g4        |   5 +
 15 files changed, 543 insertions(+), 11 deletions(-)
 create mode 100644 antlr4-maven-plugin/src/test/java/org/antlr/mojo/antlr4/Antlr4MojoTest.java
 create mode 100644 antlr4-maven-plugin/src/test/projects/importTokens/pom.xml
 create mode 100644 antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/imports/SimpleLexer.tokens
 create mode 100644 antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/test/SimpleParser.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsCustom/pom.xml
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/Hello.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestLexer.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestParser.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/imports/TestBaseLexer.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsStandard/pom.xml
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/imports/TestBaseLexer.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/Hello.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestLexer.g4
 create mode 100644 antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestParser.g4

diff --git a/antlr4-maven-plugin/pom.xml b/antlr4-maven-plugin/pom.xml
index b3dfd37e9..4c7eecbb5 100644
--- a/antlr4-maven-plugin/pom.xml
+++ b/antlr4-maven-plugin/pom.xml
@@ -48,6 +48,11 @@
   <!-- Ancilliary information for completeness -->
   <inceptionYear>2009</inceptionYear>
 
+  <properties>
+    <mavenVersion>3.3.9</mavenVersion>
+    <takariLifecycleVersion>1.12.2</takariLifecycleVersion>
+  </properties>
+
   <!-- ============================================================================= -->
 
   <!-- What are we depedent on for the Mojos to execute? We need the plugin 
@@ -63,11 +68,6 @@
       <version>3.0.5</version>
       <scope>compile</scope>
     </dependency>
-    <dependency>
-      <groupId>org.apache.maven</groupId>
-      <artifactId>maven-project</artifactId>
-      <version>2.2.1</version>
-    </dependency>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-compiler-api</artifactId>
@@ -93,21 +93,50 @@
       <version>4.11</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>org.apache.maven.shared</groupId>
-      <artifactId>maven-plugin-testing-harness</artifactId>
-      <version>1.1</version>
-      <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>org.apache.maven.plugin-tools</groupId>
       <artifactId>maven-plugin-annotations</artifactId>
       <version>3.2</version>
       <scope>provided</scope>
     </dependency>
+    <dependency>
+      <groupId>io.takari.maven.plugins</groupId>
+        <artifactId>takari-plugin-testing</artifactId>
+        <version>2.9.0</version>
+        <scope>test</scope>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.maven</groupId>
+        <artifactId>maven-core</artifactId>
+        <version>${mavenVersion}</version>
+        <scope>test</scope>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.maven</groupId>
+        <artifactId>maven-compat</artifactId>
+        <version>${mavenVersion}</version>
+        <scope>test</scope>
+    </dependency>
+    <dependency>
+        <groupId>org.codehaus.plexus</groupId>
+        <artifactId>plexus-utils</artifactId>
+        <version>3.0.15</version>
+        <scope>provided</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-project</artifactId>
+      <version>2.2.1</version>
+    </dependency>
   </dependencies>
 
   <build>
+    <testSourceDirectory>src/test</testSourceDirectory>
+    <testResources>
+      <testResource>
+        <directory>src/test/resources</directory>
+      </testResource>
+    </testResources>
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
@@ -132,6 +161,21 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+         <groupId>io.takari.maven.plugins</groupId>
+         <artifactId>takari-lifecycle-plugin</artifactId>
+         <version>${takariLifecycleVersion}</version>
+         <extensions>true</extensions>
+         <executions>
+           <execution>
+             <id>testProperties</id>
+             <phase>process-test-resources</phase>
+             <goals>
+               <goal>testProperties</goal>
+             </goals>
+           </execution>
+         </executions>
+       </plugin>
     </plugins>
   </build>
 
diff --git a/antlr4-maven-plugin/src/test/java/org/antlr/mojo/antlr4/Antlr4MojoTest.java b/antlr4-maven-plugin/src/test/java/org/antlr/mojo/antlr4/Antlr4MojoTest.java
new file mode 100644
index 000000000..1190adc3a
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/java/org/antlr/mojo/antlr4/Antlr4MojoTest.java
@@ -0,0 +1,319 @@
+package org.antlr.mojo.antlr4;
+
+import io.takari.maven.testing.TestMavenRuntime;
+import io.takari.maven.testing.TestResources;
+
+import org.apache.maven.execution.MavenSession;
+import org.apache.maven.plugin.MojoExecution;
+import org.apache.maven.project.MavenProject;
+
+import org.codehaus.plexus.util.xml.Xpp3Dom;
+
+import static org.junit.Assert.*;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.AbstractMap;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+
+public class Antlr4MojoTest {
+    @Rule
+    public final TestResources resources = new TestResources();
+
+    @Rule
+    public final TestMavenRuntime maven = new TestMavenRuntime();
+
+    @Test
+    public void importTokens() throws Exception {
+        Map.Entry<ByteArrayOutputStream, PrintStream> stdout = redirect();
+        ByteArrayOutputStream output = stdout.getKey();
+
+        try {
+            File baseDir = resources.getBasedir("importTokens");
+            File antlrDir = new File(baseDir, "src/main/antlr4");
+
+            File tokens = new File(antlrDir, "imports/SimpleLexer.tokens");
+
+            MavenProject project = maven.readMavenProject(baseDir);
+            MavenSession session = maven.newMavenSession(project);
+            MojoExecution exec = maven.newMojoExecution("antlr4");
+
+            ////////////////////////////////////////////////////////////////////////
+            // 1st - all grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            maven.executeMojo(session, project, exec);
+
+            assertEquals(Arrays.asList("test/SimpleParser.g4"), processAndReset(output));
+
+            ////////////////////////////////////////////////////////////////////////
+            // 2nd - nothing has been modified, no grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            maven.executeMojo(session, project, exec);
+
+            assertEquals(Collections.emptyList(), processAndReset(output));
+
+            ////////////////////////////////////////////////////////////////////////
+            // 3rd - the imported grammar changed, every dependency has to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            String original = modify(tokens);
+
+            try {
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("test/SimpleParser.g4"),
+                    processAndReset(output));
+            } finally {
+                write(tokens, original);
+            }
+        } finally {
+            System.setOut(stdout.getValue());
+        }
+    }
+
+    @Test
+    public void importsCustomLayout() throws Exception {
+        Map.Entry<ByteArrayOutputStream, PrintStream> stdout = redirect();
+        ByteArrayOutputStream output = stdout.getKey();
+
+        try {
+            File baseDir = resources.getBasedir("importsCustom");
+            File antlrDir = new File(baseDir, "src/main/antlr4");
+            File generatedSources = new File(baseDir, "target/generated-sources/antlr4");
+
+            File baseGrammar = new File(antlrDir, "imports/TestBaseLexer.g4");
+            File lexerGrammar = new File(antlrDir, "TestLexer.g4");
+            File parserGrammar = new File(antlrDir, "TestParser.g4");
+            File lexerTokens = new File(generatedSources, "TestLexer.tokens");
+
+            Xpp3Dom outputDirectory = TestMavenRuntime.newParameter("outputDirectory",
+                    "src/main/java/com/foo");
+            Xpp3Dom arguments = new Xpp3Dom("arguments");
+            arguments.addChild(TestMavenRuntime.newParameter("argument", "-package"));
+            arguments.addChild(TestMavenRuntime.newParameter("argument", "foo"));
+
+            MavenProject project = maven.readMavenProject(baseDir);
+            MavenSession session = maven.newMavenSession(project);
+            MojoExecution exec = maven.newMojoExecution("antlr4", outputDirectory,
+                    arguments);
+
+            ////////////////////////////////////////////////////////////////////////
+            // 1st - all grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            maven.executeMojo(session, project, exec);
+
+            assertEquals(Arrays.asList("Hello.g4", "TestLexer.g4", "TestParser.g4"),
+                processAndReset(output));
+
+            ////////////////////////////////////////////////////////////////////////
+            // 2nd - nothing has been modified, no grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            maven.executeMojo(session, project, exec);
+
+            assertEquals(Collections.emptyList(), processAndReset(output));
+
+            ////////////////////////////////////////////////////////////////////////
+            // 3rd - the imported grammar changed, every dependency has to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            // modify the grammar to make checksum comparison detect a change
+            String original = modify(baseGrammar);
+
+            try {
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("TestLexer.g4", "TestParser.g4"),
+                    processAndReset(output));
+            } finally {
+                write(baseGrammar, original);
+            }
+
+            ////////////////////////////////////////////////////////////////////////
+            // 4th - the lexer grammar changed, the parser grammar has to be processed as well
+            ////////////////////////////////////////////////////////////////////////
+
+            // modify the grammar to make checksum comparison detect a change
+            original = modify(lexerGrammar);
+
+            try {
+                lexerTokens.delete();
+
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("TestLexer.g4", "TestParser.g4"),
+                    processAndReset(output));
+            } finally {
+                write(lexerGrammar, original);
+            }
+
+            ////////////////////////////////////////////////////////////////////////
+            // 5th - the parser grammar changed, no other grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            // modify the grammar to make checksum comparison detect a change
+            original = modify(parserGrammar);
+
+            try {
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("TestParser.g4"), processAndReset(output));
+            } finally {
+                write(parserGrammar, original);
+            }
+        } finally {
+            System.out.flush();
+            System.setOut(stdout.getValue());
+        }
+    }
+
+    @Test
+    public void importsStandardLayout() throws Exception {
+        Map.Entry<ByteArrayOutputStream, PrintStream> stdout = redirect();
+        ByteArrayOutputStream output = stdout.getKey();
+
+        try {
+            File baseDir = resources.getBasedir("importsStandard");
+            File antlrDir = new File(baseDir, "src/main/antlr4");
+            File generatedSources = new File(baseDir, "target/generated-sources/antlr4");
+
+            File baseGrammar = new File(antlrDir, "imports/TestBaseLexer.g4");
+            File lexerGrammar = new File(antlrDir, "test/TestLexer.g4");
+            File parserGrammar = new File(antlrDir, "test/TestParser.g4");
+            File lexerTokens = new File(generatedSources, "TestLexer.tokens");
+
+            MavenProject project = maven.readMavenProject(baseDir);
+            MavenSession session = maven.newMavenSession(project);
+            MojoExecution exec = maven.newMojoExecution("antlr4");
+
+            ////////////////////////////////////////////////////////////////////////
+            // 1st - all grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            maven.executeMojo(session, project, exec);
+
+            assertEquals(Arrays.asList("test/Hello.g4", "test/TestLexer.g4",
+                    "test/TestParser.g4"), processAndReset(output));
+
+            ////////////////////////////////////////////////////////////////////////
+            // 2nd - nothing has been modified, no grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            maven.executeMojo(session, project, exec);
+
+            assertEquals(Collections.emptyList(), processAndReset(output));
+
+            ////////////////////////////////////////////////////////////////////////
+            // 3rd - the imported grammar changed, every dependency has to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            // modify the grammar to make checksum comparison detect a change
+            String original = modify(baseGrammar);
+
+            try {
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("test/TestLexer.g4", "test/TestParser.g4"),
+                    processAndReset(output));
+            } finally {
+                write(baseGrammar, original);
+            }
+
+            ////////////////////////////////////////////////////////////////////////
+            // 4th - the lexer grammar changed, the parser grammar has to be processed as well
+            ////////////////////////////////////////////////////////////////////////
+
+            // modify the grammar to make checksum comparison detect a change
+            original = modify(lexerGrammar);
+
+            try {
+                lexerTokens.delete();
+
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("test/TestLexer.g4", "test/TestParser.g4"),
+                    processAndReset(output));
+            } finally {
+                write(lexerGrammar, original);
+            }
+
+            ////////////////////////////////////////////////////////////////////////
+            // 5th - the parser grammar changed, no other grammars have to be processed
+            ////////////////////////////////////////////////////////////////////////
+
+            // modify the grammar to make checksum comparison detect a change
+            original = modify(parserGrammar);
+
+            try {
+                maven.executeMojo(session, project, exec);
+
+                assertEquals(Arrays.asList("test/TestParser.g4"),
+                    processAndReset(output));
+            } finally {
+                write(parserGrammar, original);
+            }
+        } finally {
+            System.out.flush();
+            System.setOut(stdout.getValue());
+        }
+    }
+
+    private List<String> processAndReset(ByteArrayOutputStream output) {
+        Pattern pattern = Pattern.compile("Processing grammar: (.+)");
+        Matcher matcher = pattern.matcher(output.toString());
+
+        // we reset here simply for convenience
+        output.reset();
+
+        List<String> result = new ArrayList<String>();
+
+        while (matcher.find()) {
+            result.add(matcher.group(1));
+        }
+
+        Collections.sort(result);
+
+        return result;
+    }
+
+    private String modify(File file) throws IOException {
+        String content = text(file);
+        write(file, content + "\n");
+
+        return content;
+    }
+
+    private void write(File file, String text) throws IOException {
+        Files.write(file.toPath(), text.getBytes(StandardCharsets.UTF_8));
+    }
+
+    private String text(File file) throws IOException {
+        return new String(Files.readAllBytes(file.toPath()), StandardCharsets.UTF_8);
+    }
+
+    private Map.Entry<ByteArrayOutputStream, PrintStream> redirect() {
+        // there does not seem to be a clean way to intercept logging output
+        ByteArrayOutputStream buf = new ByteArrayOutputStream();
+        PrintStream old = System.out;
+        System.setOut(new PrintStream(buf));
+
+        return new AbstractMap.SimpleEntry<ByteArrayOutputStream, PrintStream>(buf, old);
+    }
+}
diff --git a/antlr4-maven-plugin/src/test/projects/importTokens/pom.xml b/antlr4-maven-plugin/src/test/projects/importTokens/pom.xml
new file mode 100644
index 000000000..08fd320a0
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importTokens/pom.xml
@@ -0,0 +1,27 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>import.tokens</groupId>
+  <artifactId>importTokens</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+  <name>Test importing tokens file</name>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.11</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+          <artifactId>antlr4-maven-plugin</artifactId>
+        <configuration>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/imports/SimpleLexer.tokens b/antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/imports/SimpleLexer.tokens
new file mode 100644
index 000000000..4637d6ebb
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/imports/SimpleLexer.tokens
@@ -0,0 +1,3 @@
+ID=1
+INT=2
+SEMI=3
diff --git a/antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/test/SimpleParser.g4 b/antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/test/SimpleParser.g4
new file mode 100644
index 000000000..bbd8274a4
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importTokens/src/main/antlr4/test/SimpleParser.g4
@@ -0,0 +1,8 @@
+parser grammar SimpleParser;
+options {
+  // get token types from SimpleLexer.tokens; don't name it
+  // SimpleParser.tokens as ANTLR will overwrite!
+  tokenVocab=SimpleLexer; 
+}
+
+s : ( ID | INT )* SEMI ;
diff --git a/antlr4-maven-plugin/src/test/projects/importsCustom/pom.xml b/antlr4-maven-plugin/src/test/projects/importsCustom/pom.xml
new file mode 100644
index 000000000..0c7988fe5
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsCustom/pom.xml
@@ -0,0 +1,42 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>imports.custom</groupId>
+  <artifactId>importsCustom</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+  <name>Test importing, custom layout</name>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.11</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <artifactId>antlr4-maven-plugin</artifactId>
+        <configuration>
+          <outputDirectory>${basedir}/src/main/java/com/foo</outputDirectory>
+					<arguments>
+						<argument>-visitor</argument>
+						<argument>-no-listener</argument>
+						<argument>-Xlog</argument>
+						<argument>-package</argument>
+						<argument>com.foo</argument>
+					</arguments>
+        </configuration>
+				<executions>
+					<execution>
+						<goals>
+							<goal>antlr4</goal>
+						</goals>
+					</execution>
+				</executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/Hello.g4 b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/Hello.g4
new file mode 100644
index 000000000..e38ac8781
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/Hello.g4
@@ -0,0 +1,4 @@
+grammar Hello;
+r  : 'hello' ID ;
+ID : [a-z]+ ;
+WS : [ \r\t\n]+ -> skip ;
\ No newline at end of file
diff --git a/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestLexer.g4 b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestLexer.g4
new file mode 100644
index 000000000..668b76496
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestLexer.g4
@@ -0,0 +1,6 @@
+lexer grammar TestLexer;
+
+import TestBaseLexer;
+
+WS    :  Whitespace+              -> skip;
+TEXT  :  ~[<&]+ ; // match any 16 bit char other than < and &
\ No newline at end of file
diff --git a/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestParser.g4 b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestParser.g4
new file mode 100644
index 000000000..5c25961e1
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/TestParser.g4
@@ -0,0 +1,5 @@
+parser grammar TestParser;
+
+options { tokenVocab=TestLexer; }
+
+document  :  (Comment | Name) EOF ;
\ No newline at end of file
diff --git a/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/imports/TestBaseLexer.g4 b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/imports/TestBaseLexer.g4
new file mode 100644
index 000000000..5fcc6d353
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsCustom/src/main/antlr4/imports/TestBaseLexer.g4
@@ -0,0 +1,16 @@
+lexer grammar TestBaseLexer;
+
+tokens  { Name }
+
+// Default "mode": Everything OUTSIDE of a tag
+Comment     :  '<!--' .*? '-->' ;
+CDSect      :  '<![CDATA[' .*? ']]>' ;
+
+fragment
+Whitespace  :  ' ' | '\n' | '\t' | '\r' ;
+
+fragment
+Hexdigit    :  [a-fA-F0-9] ;
+
+fragment
+Digit       :  [0-9] ;
diff --git a/antlr4-maven-plugin/src/test/projects/importsStandard/pom.xml b/antlr4-maven-plugin/src/test/projects/importsStandard/pom.xml
new file mode 100644
index 000000000..6d532b781
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsStandard/pom.xml
@@ -0,0 +1,27 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>imports.standard</groupId>
+  <artifactId>importsStandard</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+  <name>Test importing, standard layout</name>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.11</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+          <artifactId>antlr4-maven-plugin</artifactId>
+        <configuration>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/imports/TestBaseLexer.g4 b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/imports/TestBaseLexer.g4
new file mode 100644
index 000000000..5fcc6d353
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/imports/TestBaseLexer.g4
@@ -0,0 +1,16 @@
+lexer grammar TestBaseLexer;
+
+tokens  { Name }
+
+// Default "mode": Everything OUTSIDE of a tag
+Comment     :  '<!--' .*? '-->' ;
+CDSect      :  '<![CDATA[' .*? ']]>' ;
+
+fragment
+Whitespace  :  ' ' | '\n' | '\t' | '\r' ;
+
+fragment
+Hexdigit    :  [a-fA-F0-9] ;
+
+fragment
+Digit       :  [0-9] ;
diff --git a/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/Hello.g4 b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/Hello.g4
new file mode 100644
index 000000000..e38ac8781
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/Hello.g4
@@ -0,0 +1,4 @@
+grammar Hello;
+r  : 'hello' ID ;
+ID : [a-z]+ ;
+WS : [ \r\t\n]+ -> skip ;
\ No newline at end of file
diff --git a/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestLexer.g4 b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestLexer.g4
new file mode 100644
index 000000000..668b76496
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestLexer.g4
@@ -0,0 +1,6 @@
+lexer grammar TestLexer;
+
+import TestBaseLexer;
+
+WS    :  Whitespace+              -> skip;
+TEXT  :  ~[<&]+ ; // match any 16 bit char other than < and &
\ No newline at end of file
diff --git a/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestParser.g4 b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestParser.g4
new file mode 100644
index 000000000..5c25961e1
--- /dev/null
+++ b/antlr4-maven-plugin/src/test/projects/importsStandard/src/main/antlr4/test/TestParser.g4
@@ -0,0 +1,5 @@
+parser grammar TestParser;
+
+options { tokenVocab=TestLexer; }
+
+document  :  (Comment | Name) EOF ;
\ No newline at end of file