feat: support for BOM POM's i.e. maven dependencyManagement

jbang will now if and only if the very first dependency has a `@pom`
classifier, download it and load it as pom file in shrinkwrap.

Example:

```java
//DEPS io.quarkus:quarkus-bom:1.11.0.Final@pom
//DEPS io.quarkus:quarkus-resteasy
//DEPS io.quarkus:quarkus-smallrye-openapi
//DEPS io.quarkus:quarkus-swagger-ui
```

Then that pom file dependency management (and dependencies) gets listened to.

Fixes jbangdev#63

build.gradle

@@ -30,8 +30,12 @@ dependencies {
 	implementation 'org.codehaus.plexus:plexus-java:1.0.5'
 	implementation 'com.google.code.gson:gson:2.8.6'
 	implementation 'org.jsoup:jsoup:1.13.1'
-	implementation 'org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-api:3.1.4'
-	implementation 'org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-impl-maven:3.1.4'
+
+	implementation 'com.github.jbangdev.jbang-resolver:shrinkwrap-resolver-api:3.1.5-allowpom'
+	implementation 'com.github.jbangdev.jbang-resolver:shrinkwrap-resolver-impl-maven:3.1.5-allowpom'
+
+	//implementation 'org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-api:3.1.4'
+	//implementation 'org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-impl-maven:3.1.4'
 	implementation "org.slf4j:slf4j-nop:1.7.30"
 	implementation "org.jboss:jandex:2.2.2.Final"
 	//implementation 'org.apache.maven:maven-aether-provider:3.0.5'
@@ -145,8 +149,11 @@ compileTestJava {
 
 shadowJar {
 	minimize()  {
-		exclude(dependency('org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-spi:.*'))
-		exclude(dependency('org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-impl-maven:.*'))
+		//exclude(dependency('org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-spi:.*'))
+		//exclude(dependency('org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-impl-maven:.*'))
+		exclude(dependency('com.github.jbangdev.jbang-resolver:shrinkwrap-resolver-spi:.*'))
+		exclude(dependency('com.github.jbangdev.jbang-resolver:shrinkwrap-resolver-impl-maven:.*'))
+
 		//exclude(dependency('org.slf4j:slf4j-api:.*'))
 		exclude(dependency('org.slf4j:slf4j-nop:.*'))
 		exclude(dependency('org.jboss.logging:jboss-logging:.*'))

readme.adoc

@@ -530,6 +530,28 @@ $ ./classpath_example.java
 1 [main] INFO classpath_example  - Hello from Java!
 ----
 
+=== Managed dependencies ("BOM POM"'s)
+
+When using libraries and frameworks it can get tedious to mange and update multiple versions.
+For that jbang started since 0.62 to support so called "BOM POM"'s which are commonly used for managing versions.
+
+You use it by having as the very first dependency a `@pom` reference. This first reference will be used
+to define your managed dependences. Below is an example how that could look like when using Quarkus:
+
+```java
+//DEPS io.quarkus:quarkus-bom:1.11.0.Final@pom
+//DEPS io.quarkus:quarkus-resteasy
+//DEPS io.quarkus:quarkus-smallrye-openapi
+//DEPS io.quarkus:quarkus-swagger-ui
+```
+
+Notice the `@pom` at first line and then following dependencies are not required to use explicit versions.
+
+[NOTE]
+At the moment jbang support only one bom pom; in future it should be expanded to multiple.
+For now you can workaround this by reusing a published pom that includes all the dependency management
+sections you need.
+
 === Using links to Git sources
 
 Instead of gradle-style locators you can also use URLs to projects on GitHub, GitLab or BitBucket.

src/main/java/dev/jbang/DependencyUtil.java

@@ -1,10 +1,16 @@
 package dev.jbang;
 
-import static dev.jbang.Settings.CP_SEPARATOR;
-import static dev.jbang.Util.errorMsg;
-import static dev.jbang.Util.infoHeader;
-import static dev.jbang.Util.infoMsg;
-import static dev.jbang.Util.infoMsgFmt;
+import org.jboss.shrinkwrap.resolver.api.maven.ConfigurableMavenResolverSystem;
+import org.jboss.shrinkwrap.resolver.api.maven.Maven;
+import org.jboss.shrinkwrap.resolver.api.maven.MavenFormatStage;
+import org.jboss.shrinkwrap.resolver.api.maven.MavenResolvedArtifact;
+import org.jboss.shrinkwrap.resolver.api.maven.MavenStrategyStage;
+import org.jboss.shrinkwrap.resolver.api.maven.MavenWorkingSession;
+import org.jboss.shrinkwrap.resolver.api.maven.PackagingType;
+import org.jboss.shrinkwrap.resolver.api.maven.PomEquippedResolveStage;
+import org.jboss.shrinkwrap.resolver.api.maven.coordinate.MavenCoordinate;
+import org.jboss.shrinkwrap.resolver.api.maven.coordinate.MavenCoordinates;
+import org.jboss.shrinkwrap.resolver.impl.maven.MavenWorkingSessionContainer;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -16,14 +22,11 @@
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
-import org.jboss.shrinkwrap.resolver.api.maven.ConfigurableMavenResolverSystem;
-import org.jboss.shrinkwrap.resolver.api.maven.Maven;
-import org.jboss.shrinkwrap.resolver.api.maven.MavenFormatStage;
-import org.jboss.shrinkwrap.resolver.api.maven.MavenResolvedArtifact;
-import org.jboss.shrinkwrap.resolver.api.maven.MavenStrategyStage;
-import org.jboss.shrinkwrap.resolver.api.maven.PackagingType;
-import org.jboss.shrinkwrap.resolver.api.maven.coordinate.MavenCoordinate;
-import org.jboss.shrinkwrap.resolver.api.maven.coordinate.MavenCoordinates;
+import static dev.jbang.Settings.CP_SEPARATOR;
+import static dev.jbang.Util.errorMsg;
+import static dev.jbang.Util.infoHeader;
+import static dev.jbang.Util.infoMsg;
+import static dev.jbang.Util.infoMsgFmt;
 
 public class DependencyUtil {
 
@@ -42,9 +45,12 @@ public class DependencyUtil {
 		aliasToRepos.put("sponge", "https://repo.spongepowered.org/maven");
 	}
 
-	public static final Pattern gavPattern = Pattern.compile(
+	public static final Pattern fullGavPattern = Pattern.compile(
 			"^(?<groupid>[^:]*):(?<artifactid>[^:]*):(?<version>[^:@]*)(:(?<classifier>[^@]*))?(@(?<type>.*))?$");
 
+	public static final Pattern gavPattern = Pattern.compile(
+			"^(?<groupid>[^:]*):(?<artifactid>[^:]*)(:(?<version>[^:@]*))?(:(?<classifier>[^@]*))?(@(?<type>.*))?$");
+
 	public ModularClassPath resolveDependencies(List<String> deps, List<MavenRepo> repos,
 			boolean offline, boolean loggingEnabled) {
 		return resolveDependencies(deps, repos, offline, loggingEnabled, true);
@@ -131,26 +137,62 @@ public List<ArtifactInfo> resolveDependenciesViaAether(List<String> depIds, List
 			mavenRepo.apply(resolver);
 		});
 
+		MavenWorkingSession xyz = ((MavenWorkingSessionContainer) resolver).getMavenWorkingSession();
 		System.setProperty("maven.repo.local", Settings.getLocalMavenRepo().toPath().toAbsolutePath().toString());
 
+		List<MavenCoordinate> deps = depIds.stream().map(it -> depIdToArtifact(it)).collect(Collectors.toList());
+
+		PomEquippedResolveStage pomResolve = null;
+
+		if (!depIds.isEmpty()) {
+			MavenCoordinate mc = depIdToArtifact(depIds.get(0));
+			if (PackagingType.POM.equals(mc.getType())) {
+				if (loggingEnabled) {
+					infoMsg("Loading " + mc);
+				}
+				System.setProperty("jbang-allowpom", "true"); // big hack to trick shrinkwrap in actually get pom
+																// location
+				MavenStrategyStage resolve = resolver.resolve(mc.toCanonicalForm());
+				pomResolve = resolver.loadPomFromFile(resolve.withoutTransitivity().asSingleFile());
+				System.getProperties().remove("jbang-allowpom");
+				depIds.remove(0);
+			}
+		}
+
+		final PomEquippedResolveStage ps = pomResolve;
+
 		return depIds.stream().flatMap(it -> {
 
+			MavenCoordinate artifact = depIdToArtifact(it);
+
+			if (PackagingType.POM.equals(artifact.getType())) {
+				// proactively avoiding that we break users in future
+				// when we support more than one BOM POM
+				throw new ExitException(1, "POM imports as found in " + it + " is only supported as the first import.");
+			}
+
 			if (loggingEnabled) {
 				infoHeader();
 				infoMsgFmt("    Resolving %s...", it);
 			}
 
 			List<MavenResolvedArtifact> artifacts;
 			try {
-				MavenStrategyStage resolve = resolver.resolve(depIdToArtifact(it).toCanonicalForm());
+				MavenStrategyStage resolve;
 				MavenFormatStage stage = null;
+				if (ps != null) {
+					resolve = ps.resolve(artifact.toCanonicalForm());
+				} else {
+					resolve = resolver.resolve(artifact.toCanonicalForm());
+				}
 
 				if (transitively) {
 					stage = resolve.withTransitivity();
 				} else {
 					stage = resolve.withoutTransitivity();
 				}
 				artifacts = stage.asList(MavenResolvedArtifact.class); // , RUNTIME);
+
 			} catch (RuntimeException e) {
 				throw new ExitException(1, "Could not resolve dependency", e);
 			}
@@ -177,7 +219,7 @@ public String decodeEnv(String value) {
 	}
 
 	public static boolean looksLikeAGav(String candidate) {
-		Matcher gav = gavPattern.matcher(candidate);
+		Matcher gav = fullGavPattern.matcher(candidate);
 		gav.find();
 		return (gav.matches());
 	}
@@ -211,7 +253,7 @@ public MavenCoordinate depIdToArtifact(String depId) {
 
 	public String formatVersion(String version) {
 		// replace + with open version range for maven
-		if (version.endsWith("+")) {
+		if (version != null && version.endsWith("+")) {
 			return "[" + removeLastCharOptional(version) + ",)";
 		} else {
 			return version;

src/test/java/dev/jbang/DependencyResolverTest.java

@@ -213,18 +213,18 @@ protected boolean supportsModules(String requestedVersion) {
 
 	/*
 	 * @Ignore("BOM import not yet figured out with shrinkwrap")
-	 * 
-	 * @Test void testImportPOM() {
-	 * 
-	 * List<String> deps =
-	 * Arrays.asList("com.microsoft.azure:azure-bom:1.0.0.M1@pom",
-	 * "com.microsoft.azure:azure");
-	 * 
-	 * String classpath = new DependencyUtil().resolveDependencies(deps,
-	 * Collections.emptyList(), false, true);
-	 * 
-	 * assertEquals(46, classpath.split(Settings.CP_SEPARATOR).length);
-	 * 
-	 * }
 	 */
+	@Test
+	void testImportPOM() {
+
+		List<String> deps = Arrays.asList("com.microsoft.azure:azure-bom:1.0.0.M1@pom",
+				"com.microsoft.azure:azure");
+
+		ModularClassPath classpath = new DependencyUtil().resolveDependencies(deps,
+				Collections.emptyList(), false, true);
+
+		assertEquals(62, classpath.getArtifacts().size());
+
+	}
+
 }