#13: Accept version from parent project in file pom.xml, too. (#14)

.gitignore

@@ -31,4 +31,6 @@ venv/
 *.orig
 *.old
 *.md.html
-*.flattened-pom.xml
+*.flattened-pom.xml
+/.apt_generated/
+/.apt_generated_tests/

.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,5 @@
+eclipse.preferences.version=1
+encoding//src/main/java=UTF-8
+encoding//src/test/java=UTF-8
+encoding//src/test/resources=UTF-8
+encoding/<project>=UTF-8

.settings/org.eclipse.m2e.core.prefs

@@ -0,0 +1,4 @@
+activeProfiles=
+eclipse.preferences.version=1
+resolveWorkspaceProjects=true
+version=1

doc/changes/changes_1.2.0.md

@@ -0,0 +1,17 @@
+# Maven Project Version Getter 1.2.0, released 2022-09-27
+
+Code name: Version from parent project in file `pom.xml`
+
+## Summary
+
+Enhanced Maven Project Version Getter to accept version from parent project in file `pom.xml`, too.
+
+## Features
+
+* #13: Accept version from parent project in file `pom.xml`, too.
+
+## Dependency Updates
+
+### Plugin Dependency Updates
+
+* Updated `com.exasol:project-keeper-maven-plugin:2.6.2` to `2.8.0`

error_code_config.yml

@@ -2,4 +2,4 @@ error-tags:
   MPVG:
     packages:
       - com.exasol.mavenprojectversiongetter
-    highest-index: 1
+    highest-index: 2

pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.exasol</groupId>
     <artifactId>maven-project-version-getter</artifactId>
-    <version>1.1.1</version>
+    <version>1.2.0</version>
     <name>Maven Project Version Getter</name>
     <description>Java helper for getting the current project's version from test code.</description>
     <url>https://github.com/exasol/maven-project-version-getter/</url>
@@ -50,7 +50,7 @@
             <plugin>
                 <groupId>com.exasol</groupId>
                 <artifactId>project-keeper-maven-plugin</artifactId>
-                <version>2.6.2</version>
+                <version>2.8.0</version>
                 <executions>
                     <execution>
                         <goals>
@@ -64,7 +64,7 @@
     <parent>
         <artifactId>maven-project-version-getter-generated-parent</artifactId>
         <groupId>com.exasol</groupId>
-        <version>1.1.1</version>
+        <version>1.2.0</version>
         <relativePath>pk_generated_parent.pom</relativePath>
     </parent>
 </project>

src/main/java/com/exasol/mavenprojectversiongetter/MavenProjectVersionGetter.java

@@ -24,13 +24,44 @@ private MavenProjectVersionGetter() {
 
     /**
      * Get the version of the current project.
-     * 
+     *
      * @return version string
      */
     public static String getCurrentProjectVersion() {
         return getProjectVersion(Path.of("pom.xml"));
     }
 
+    /**
+     * Get the version of the current project as specified for the project itself or for its parent.
+     *
+     * @return version string
+     */
+    public static String getVersionOfCurrentProjectOrParent() {
+        return getVersionOfProjectOrParent(Path.of("pom.xml"));
+    }
+
+    /**
+     * Get the version as specified for the project itself or for its parent
+     *
+     * @param pomFile path to {@code pom.xml} to get the version from
+     * @return version string
+     */
+    public static String getVersionOfProjectOrParent(final Path pomFile) {
+        final String version = getProjectVersion(pomFile);
+        final String parentVersion = getParentVersion(pomFile);
+        if (version.isEmpty()) {
+            return parentVersion;
+        }
+        if (parentVersion.isEmpty() || parentVersion.equals(version)) {
+            return version;
+        }
+        throw new VersionGetterException(ExaError.messageBuilder("E-MPVG-2")
+                .message("Inconsistent version information in file {{pom file}}:" //
+                        + " project version is {{project version}}, while parent version is {{parent version}}.", //
+                        pomFile, version, parentVersion)
+                .toString());
+    }
+
     /**
      * Get the version of a given project.
      *
@@ -51,7 +82,17 @@ public static String getProjectRevision(final Path pomFile) {
         return getPropertyOfXmlFile(pomFile, "/project/properties/revision");
     }
 
-    private static String getPropertyOfXmlFile(Path pomFile, String propertyXPath) {
+    /**
+     * Get the version of the parent project.
+     *
+     * @param pomFile path to {@code pom.xml} to get the parent version from
+     * @return version string
+     */
+    public static String getParentVersion(final Path pomFile) {
+        return getPropertyOfXmlFile(pomFile, "/project/parent/version");
+    }
+
+    private static String getPropertyOfXmlFile(final Path pomFile, final String propertyXPath) {
         try {
             final var documentBuilderFactory = DocumentBuilderFactory.newInstance();
             documentBuilderFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
@@ -60,9 +101,24 @@ private static String getPropertyOfXmlFile(Path pomFile, String propertyXPath) {
             final var xPath = XPathFactory.newInstance().newXPath();
             return xPath.compile(propertyXPath).evaluate(pom);
         } catch (final XPathExpressionException | SAXException | ParserConfigurationException | IOException exception) {
-            throw new IllegalStateException(ExaError.messageBuilder("E-MPVG-1")
+            throw new VersionGetterException(ExaError.messageBuilder("E-MPVG-1")
                     .message("Failed to get current project version from pom file {{file}}.", pomFile).toString(),
                     exception);
         }
     }
+
+    /**
+     * Exception thrown by MavenProjectVersionGetter
+     */
+    public static class VersionGetterException extends RuntimeException {
+        private static final long serialVersionUID = 1L;
+
+        VersionGetterException(final String message, final Exception exception) {
+            super(message, exception);
+        }
+
+        VersionGetterException(final String message) {
+            super(message);
+        }
+    }
 }

src/test/java/com/exasol/mavenprojectversiongetter/MavenProjectVersionGetterTest.java

@@ -1,8 +1,7 @@
 package com.exasol.mavenprojectversiongetter;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.startsWith;
+import static org.hamcrest.Matchers.*;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.io.IOException;
@@ -12,6 +11,8 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
+import com.exasol.mavenprojectversiongetter.MavenProjectVersionGetter.VersionGetterException;
+
 class MavenProjectVersionGetterTest {
 
     @Test
@@ -21,6 +22,24 @@ void testReadVersion(@TempDir final Path tempDir) throws IOException {
         assertThat(MavenProjectVersionGetter.getProjectVersion(pomFile), equalTo("1.2.3"));
     }
 
+    @Test
+    void getVersionOfCurrentProjectOrParent(@TempDir final Path tempDir) throws IOException {
+        final Path pomFile = tempDir.resolve("pom.xml");
+        Files.writeString(pomFile, "<project><parent><version>2.3.4</version></parent></project>");
+        assertThat(MavenProjectVersionGetter.getVersionOfProjectOrParent(pomFile), equalTo("2.3.4"));
+    }
+
+    @Test
+    void inconsistentVersionsOfProjectAndParent(@TempDir final Path tempDir) throws IOException {
+        final Path pomFile = tempDir.resolve("pom.xml");
+        Files.writeString(pomFile,
+                "<project><version>1.2.3</version><parent><version>2.3.4</version></parent></project>");
+        final Exception exception = assertThrows(VersionGetterException.class,
+                () -> MavenProjectVersionGetter.getVersionOfProjectOrParent(pomFile));
+        assertThat(exception.getMessage(), matchesRegex("E-MPVG-2: Inconsistent version information in file .*pom.xml:"
+                + " project version is '1.2.3', while parent version is '2.3.4'."));
+    }
+
     @Test
     void testGetVersionOfCurrentProject() {
         assertThat(MavenProjectVersionGetter.getCurrentProjectVersion(),
@@ -30,7 +49,7 @@ void testGetVersionOfCurrentProject() {
     @Test
     void testGettingVersionFails(@TempDir final Path tempDir) {
         final Path nonExistingPomFile = tempDir.resolve("nonExistingPom.xml");
-        final IllegalStateException exception = assertThrows(IllegalStateException.class,
+        final Exception exception = assertThrows(VersionGetterException.class,
                 () -> MavenProjectVersionGetter.getProjectVersion(nonExistingPomFile));
         assertThat(exception.getMessage(), startsWith("E-MPVG-1: Failed to get current project version from pom file"));
     }