Allow definition of a tag prefix and if it's included in version (#61)

Author: MatthewMaclean

readme.md

@@ -39,6 +39,20 @@ details.branchName // is null if the repository in detached HEAD mode
 details.isCleanTag
 ```
 
+You can optionally search a subset of tags with `prefix`. Example when the tag is [email protected]:
+
+```groovy
+gitVersion(prefix:'my-product@') // -> 2.15.0
+```
+
+Valid prefixes are defined by the regex `[/@]?([A-Za-z]+[/@-])+`.
+```
+/Abc/
+Abc@
+foo-bar@
+foo/bar@
+```
+
 Tasks
 -----
 This plugin adds a `printVersion` task, which will echo the project's configured version

src/main/groovy/com/palantir/gradle/gitversion/GitVersionArgs.groovy

@@ -0,0 +1,5 @@
+package com.palantir.gradle.gitversion
+
+class GitVersionArgs {
+    String prefix = ''
+}

src/main/groovy/com/palantir/gradle/gitversion/GitVersionPlugin.groovy

@@ -28,14 +28,17 @@ import org.gradle.api.Project
 class GitVersionPlugin implements Plugin<Project> {
 
     private static final int VERSION_ABBR_LENGTH = 10
+    private static final String PREFIX_REGEX = "[/@]?([A-Za-z]+[/@-])+"
 
     void apply(Project project) {
         project.ext.gitVersion = {
-            return versionDetails(project).version
+            args = [:] ->
+                return versionDetails(project, args as GitVersionArgs).version
         }
 
         project.ext.versionDetails = {
-            return versionDetails(project)
+            args = [:] ->
+                return versionDetails(project, args as GitVersionArgs)
         }
 
         project.tasks.create('printVersion') {
@@ -47,9 +50,19 @@ class GitVersionPlugin implements Plugin<Project> {
         }
     }
 
+    static void verifyPrefix(String prefix) {
+        assert prefix != null && (prefix == "" || prefix.matches(PREFIX_REGEX)),
+                "Specified prefix `${prefix}` does not match the allowed format regex `${PREFIX_REGEX}`."
+    }
+
+    private static String stripPrefix(String description, String prefix) {
+        return !description ? description : description.replaceFirst("^${prefix}", "")
+    }
+
     @Memoized
-    private VersionDetails versionDetails(Project project) {
-        String description = gitDescribe(project)
+    private VersionDetails versionDetails(Project project, GitVersionArgs args) {
+        verifyPrefix(args.prefix)
+        String description = stripPrefix(gitDescribe(project, args.prefix), args.prefix)
         String hash = gitHash(project)
         String branchName = gitBranchName(project)
         boolean isClean = isClean(project)
@@ -64,7 +77,7 @@ class GitVersionPlugin implements Plugin<Project> {
     }
 
     @Memoized
-    private String gitDescribe(Project project) {
+    private String gitDescribe(Project project, String prefix) {
         // verify that "git" command exists (throws exception if it does not)
         GitCli.verifyGitCommandExists()
 
@@ -74,7 +87,8 @@ class GitVersionPlugin implements Plugin<Project> {
             // first to preserve this behavior in cases where this call would fail but native "git" call does not.
             new DescribeCommand(git.getRepository()).call()
 
-            return GitCli.runGitCommand(project.rootDir, "describe", "--tags", "--always", "--first-parent")
+            return GitCli.runGitCommand(project.rootDir, "describe", "--tags", "--always", "--first-parent",
+                    "--match=${prefix}*")
         } catch (Throwable t) {
             return null
         }

src/test/groovy/com/palantir/gradle/gitversion/GitVersionPluginTests.groovy

@@ -15,19 +15,17 @@
  */
 package com.palantir.gradle.gitversion
 
+import org.eclipse.jgit.api.Git
 import org.eclipse.jgit.api.MergeCommand
 import org.eclipse.jgit.lib.Ref
-
-import java.nio.file.Files
-
-import org.eclipse.jgit.api.Git
 import org.gradle.testkit.runner.BuildResult
 import org.gradle.testkit.runner.GradleRunner
 import org.junit.Rule
 import org.junit.rules.TemporaryFolder
-
 import spock.lang.Specification
 
+import java.nio.file.Files
+
 class GitVersionPluginTests extends Specification {
     @Rule
     TemporaryFolder temporaryFolder = new TemporaryFolder()
@@ -416,6 +414,53 @@ class GitVersionPluginTests extends Specification {
         buildResult.output =~ ":printVersionDetails\n1.0.0\n0\n[a-z0-9]{10}\nnull\n"
     }
 
+    def 'version filters out tags not matching prefix and strips prefix' () {
+        given:
+        buildFile << '''
+            plugins {
+                id 'com.palantir.git-version'
+            }
+            version gitVersion(prefix:"my-product@")
+            task printVersionDetails() << {
+                println versionDetails(prefix:"my-product@").lastTag
+            }
+        '''.stripIndent()
+        gitIgnoreFile << 'build'
+        Git git = Git.init().setDirectory(projectDir).call();
+        git.add().addFilepattern('.').call()
+        git.commit().setMessage('initial commit').call()
+        git.tag().setAnnotated(true).setMessage('[email protected]').setName('[email protected]').call()
+        git.commit().setMessage('commit 2').call()
+        git.tag().setAnnotated(true).setMessage('1.1.0').setName('1.1.0').call()
+
+        when:
+        BuildResult buildResult = with('printVersionDetails').build()
+
+        then:
+        buildResult.output =~ ":printVersionDetails\n1.0.0\n"
+    }
+
+    def 'test valid prefixes' () {
+        expect:
+        GitVersionPlugin.verifyPrefix("@Product@")
+        GitVersionPlugin.verifyPrefix("abc@")
+        GitVersionPlugin.verifyPrefix("abc@test@")
+        GitVersionPlugin.verifyPrefix("Abc-aBc-abC@")
+        GitVersionPlugin.verifyPrefix("foo-bar@")
+        GitVersionPlugin.verifyPrefix("foo-bar/")
+        GitVersionPlugin.verifyPrefix("foo-bar-")
+        GitVersionPlugin.verifyPrefix("foo/bar@")
+        GitVersionPlugin.verifyPrefix("Foo/Bar@")
+    }
+
+    def 'test requires @ or / or - between prefix and version' () {
+        when:
+        GitVersionPlugin.verifyPrefix("v")
+
+        then:
+        thrown AssertionError
+    }
+
     private GradleRunner with(String... tasks) {
         GradleRunner.create()
             .withPluginClasspath()