feat: add ability to create pre-release tags (#17)

Reviewed-on: #17
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

.gitea/workflows/ci.yaml

@@ -63,3 +63,37 @@ jobs:
           fi
 
           echo "New tag: ${{ steps.increment-tag.outputs.new-tag }}"
+
+  dry-run-prerelease:
+    name: Dry-Run Prerelease
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-node@v5
+        with:
+          node-version-file: .nvmrc
+      - run: npm ci
+      - name: Create prerelease tag
+        id: prerelease-tag
+        uses: ./
+        with:
+          token: ${{ secrets.GITEA_TOKEN }}
+          prerelease: "true"
+      - name: Print new tag
+        run: |
+          if [ -z "${{ steps.prerelease-tag.outputs.new-tag }}" ]; then
+            echo "No new tag found"
+            exit 1
+          fi
+
+          echo "New tag: ${{ steps.prerelease-tag.outputs.new-tag }}"
+      - name: Verify prerelease tag format
+        run: |
+          if [[ "${{ steps.prerelease-tag.outputs.new-tag }}" =~ -rc-[a-f0-9]{7,}$ ]]; then
+            echo "✓ Prerelease tag format is correct"
+          else
+            echo "✗ Prerelease tag format is incorrect. Expected format: X.Y.Z-rc-<sha>"
+            exit 1
+          fi

README.md

@@ -43,6 +43,15 @@ jobs:
     token: ${{ secrets.GITHUB_TOKEN }}
 ```
 
+### With prerelease tags
+
+```yaml
+- uses: tbehrendt/conventional-semantic-git-tag-increment@v1
+  with:
+    prerelease: "true"
+    token: ${{ secrets.GITHUB_TOKEN }}
+```
+
 ## Examples
 
 | Commit Message                      | Current Tag | New Tag  | Reason               |
@@ -52,11 +61,20 @@ jobs:
 | `feat!: change API response format` | `v1.1.1`    | `v2.0.0` | Breaking change      |
 | `docs: update README`               | `v2.0.0`    | `v2.0.1` | Documentation update |
 
+### Prerelease Examples
+
+| Commit Message                  | Current Tag | New Tag (prerelease) | Reason      |
+| ------------------------------- | ----------- | -------------------- | ----------- |
+| `feat: add user authentication` | `v1.0.0`    | `1.1.0-rc-abc123`    | New feature |
+| `fix: resolve login bug`        | `v1.1.0`    | `1.1.1-rc-def456`    | Bug fix     |
+
 ## Inputs
 
 - `last-tag` (optional): Starting tag to increment from. If not provided, uses the latest tag in the repository.
 - `token` (required): GitHub token for repository access. Use `${{ github.token }}` for public repos or a PAT for private repos.
+- `prerelease` (optional): Whether to create a prerelease tag with `-rc-<github.sha>` suffix. Defaults to `false`.
+- `max-tags` (optional): Maximum number of tags to fetch when looking for the latest non-pre-release tag. Defaults to `50`.
 
 ## Outputs
 
-- `new-tag`: The incremented semantic version tag (e.g., `1.2.3`)
+- `new-tag`: The incremented semantic version tag (e.g., `1.2.3` or `1.2.3-rc-abc123` for prerelease)

action.yml

@@ -11,6 +11,14 @@ inputs:
     description: "Token for repository access"
     required: true
     default: "${{ github.token }}"
+  prerelease:
+    description: "Whether to create a prerelease tag"
+    required: false
+    default: "false"
+  max-tags:
+    description: "Maximum number of tags to fetch when looking for the latest non-pre-release tag"
+    required: false
+    default: "50"
 
 outputs:
   new-tag:

src/main.spec.ts

@@ -149,6 +149,16 @@ describe("TagService", () => {
       const result = tagService.renderTag(tag, "v");
       expect(result).toBe("v1.2.3");
     });
+
+    it("should render tag with prerelease suffix", () => {
+      const result = tagService.renderTag(tag, "", "-rc-abc123");
+      expect(result).toBe("1.2.3-rc-abc123");
+    });
+
+    it("should render tag with prefix and prerelease suffix", () => {
+      const result = tagService.renderTag(tag, "v", "-rc-abc123");
+      expect(result).toBe("v1.2.3-rc-abc123");
+    });
   });
 
   describe("parseTag", () => {
@@ -221,7 +231,7 @@ describe("TagIncrementer", () => {
       const result = await tagIncrementer.getBaseTag(undefined);
 
       expect(result).toBe("v2.0.0");
-      expect(mockCoreService.getLogs()).toContain("INFO: Using latest tag: v2.0.0");
+      expect(mockCoreService.getLogs()).toContain("INFO: Using latest real tag: v2.0.0");
     });
 
     it("should default to 0.0.0 when no tags found", async () => {
@@ -234,6 +244,34 @@ describe("TagIncrementer", () => {
         "WARNING: No tags found in repository, defaulting to 0.0.0"
       );
     });
+
+    it("should skip pre-release tags and use latest real tag", async () => {
+      mockGitService.setMockTags([
+        { name: "v2.0.0-rc-26035c6e13" },
+        { name: "v1.2.3" },
+        { name: "v1.1.4-rc-aa512edb16" },
+        { name: "v1.0.0" },
+      ]);
+
+      const result = await tagIncrementer.getBaseTag(undefined);
+
+      expect(result).toBe("v1.2.3");
+      expect(mockCoreService.getLogs()).toContain("INFO: Using latest real tag: v1.2.3");
+    });
+
+    it("should default to 0.0.0 when only pre-release tags found", async () => {
+      mockGitService.setMockTags([
+        { name: "v2.0.0-rc-26035c6e13" },
+        { name: "v1.1.4-rc-aa512edb16" },
+      ]);
+
+      const result = await tagIncrementer.getBaseTag(undefined);
+
+      expect(result).toBe("0.0.0");
+      expect(mockCoreService.getWarnings()).toContain(
+        "WARNING: No real tags found (only pre-release tags), defaulting to 0.0.0"
+      );
+    });
   });
 
   describe("determineIncrementType", () => {
@@ -302,6 +340,28 @@ describe("TagIncrementer", () => {
 
       expect(result).toBe("2.1.1");
     });
+
+    it("should create prerelease tag when prerelease is true", async () => {
+      mockGitService.setMockTags([{ name: "v1.2.3" }]);
+      mockGitService.setMockCommit({
+        commit: { message: "feat: new feature" },
+      });
+
+      const result = await tagIncrementer.incrementTag(undefined, "ref", 50, true, "abc123");
+
+      expect(result).toBe("1.3.0-rc-abc123");
+    });
+
+    it("should not create prerelease tag when prerelease is false", async () => {
+      mockGitService.setMockTags([{ name: "v1.2.3" }]);
+      mockGitService.setMockCommit({
+        commit: { message: "feat: new feature" },
+      });
+
+      const result = await tagIncrementer.incrementTag(undefined, "ref", 50, false, "abc123");
+
+      expect(result).toBe("1.3.0");
+    });
   });
 });
 
@@ -315,14 +375,18 @@ describe("LocalGitService", () => {
 
   describe("listTags", () => {
     it("should call git command to list tags", async () => {
-      mockExecSync.mockReturnValue("v1.0.0\nv1.1.0\n" as any);
+      mockExecSync.mockReturnValue("v1.0.0\n1.1.0\n2.0.0-rc-26035c6e13\n" as any);
 
       const result = await localGitService.listTags(5);
 
       expect(mockExecSync).toHaveBeenCalledWith("git tag --sort=-version:refname", {
         encoding: "utf8",
       });
-      expect(result).toEqual([{ name: "v1.0.0" }, { name: "v1.1.0" }]);
+      expect(result).toEqual([
+        { name: "v1.0.0" },
+        { name: "1.1.0" },
+        { name: "2.0.0-rc-26035c6e13" },
+      ]);
     });
 
     it("should return empty array when no tags exist", async () => {
@@ -391,9 +455,12 @@ describe("LocalCoreService", () => {
 // Integration test example
 describe("TagIncrementer Integration", () => {
   it("should handle complete tag increment flow", async () => {
-    const mockGitService = new MockGitService([{ name: "v1.2.3" }], {
-      commit: { message: "feat: new feature" },
-    });
+    const mockGitService = new MockGitService(
+      [{ name: "v2.0.0-rc-26035c6e13" }, { name: "v1.1.4-rc-aa512edb16" }, { name: "v1.2.3" }],
+      {
+        commit: { message: "feat: new feature" },
+      }
+    );
     const mockCoreService = new MockCoreService();
     const commitAnalyzer = new ConventionalCommitAnalyzer();
     const tagService = new TagService();
@@ -410,5 +477,23 @@ describe("TagIncrementer Integration", () => {
     expect(result).toBe("1.3.0");
     expect(mockCoreService.getLogs()).toContain("INFO: Determined increment type: minor");
     expect(mockCoreService.getLogs()).toContain("INFO: New tag: 1.3.0");
+    expect(mockCoreService.getLogs()).toContain("INFO: Using latest real tag: v1.2.3");
+  });
+});
+
+describe("Prerelease Validation", () => {
+  it("should validate prerelease configuration correctly", () => {
+    // Test cases for prerelease validation logic
+    const testCases = [
+      { prerelease: true, githubSha: "abc123", shouldFail: false },
+      { prerelease: true, githubSha: "", shouldFail: true },
+      { prerelease: false, githubSha: "abc123", shouldFail: false },
+      { prerelease: false, githubSha: "", shouldFail: false },
+    ];
+
+    testCases.forEach(({ prerelease, githubSha, shouldFail }) => {
+      const result = prerelease && !githubSha;
+      expect(result).toBe(shouldFail);
+    });
   });
 });

src/main.ts

@@ -73,8 +73,8 @@ export class TagService {
     }
   }
 
-  renderTag(tag: Tag, prefix: string = ""): string {
-    return `${prefix}${tag.major}.${tag.minor}.${tag.patch}`;
+  renderTag(tag: Tag, prefix: string = "", prereleaseSuffix: string = ""): string {
+    return `${prefix}${tag.major}.${tag.minor}.${tag.patch}${prereleaseSuffix}`;
   }
 
   parseTag(tagString: string): Tag {
@@ -103,22 +103,29 @@ export class TagIncrementer {
     private tagService: TagService
   ) {}
 
-  async getBaseTag(lastTag: string | undefined): Promise<string> {
+  async getBaseTag(lastTag: string | undefined, maxTags: number = 50): Promise<string> {
     if (lastTag) {
       this.coreService.info(`Using provided tag: ${lastTag}`);
       return lastTag;
     }
 
-    this.coreService.info("Fetching tags from local repository");
-    const tags = await this.gitService.listTags(1);
+    this.coreService.info(`Fetching up to ${maxTags} tags from local repository`);
+    const tags = await this.gitService.listTags(maxTags);
 
     if (tags.length === 0) {
       this.coreService.warning("No tags found in repository, defaulting to 0.0.0");
       return "0.0.0";
     }
 
-    const baseTag = tags[0].name;
-    this.coreService.info(`Using latest tag: ${baseTag}`);
+    const realTags = tags.filter((tag) => !tag.name.includes("-rc-"));
+
+    if (realTags.length === 0) {
+      this.coreService.warning("No real tags found (only pre-release tags), defaulting to 0.0.0");
+      return "0.0.0";
+    }
+
+    const baseTag = realTags[0].name;
+    this.coreService.info(`Using latest real tag: ${baseTag}`);
     return baseTag;
   }
 
@@ -155,10 +162,16 @@ export class TagIncrementer {
     }
   }
 
-  async incrementTag(lastTag: string | undefined, ref: string): Promise<string> {
+  async incrementTag(
+    lastTag: string | undefined,
+    ref: string,
+    maxTags: number = 50,
+    prerelease: boolean = false,
+    githubSha: string = ""
+  ): Promise<string> {
     this.coreService.info(`Starting tag increment process at ref ${ref}`);
 
-    const baseTag = await this.getBaseTag(lastTag);
+    const baseTag = await this.getBaseTag(lastTag, maxTags);
     const parsedTag = this.tagService.parseTag(baseTag);
 
     this.coreService.info(
@@ -168,7 +181,9 @@ export class TagIncrementer {
     const incrementType = await this.determineIncrementType(ref);
 
     const newTag = this.tagService.bumpTag(parsedTag, incrementType);
-    const renderedTag = this.tagService.renderTag(newTag);
+
+    const prereleaseSuffix = prerelease && githubSha ? `-rc-${githubSha}` : "";
+    const renderedTag = this.tagService.renderTag(newTag, "", prereleaseSuffix);
 
     this.coreService.info(`New tag: ${renderedTag}`);
     this.coreService.info(
@@ -242,12 +257,27 @@ export async function run(): Promise<void> {
     const coreService = new LocalCoreService();
 
     const lastTag = coreService.getInput("last-tag");
+    const maxTagsInput = coreService.getInput("max-tags");
+    const maxTags = parseInt(maxTagsInput || "50", 10);
+    const prereleaseInput = coreService.getInput("prerelease");
+    const prerelease = prereleaseInput === "true";
+    const githubSha = process.env.GITHUB_SHA || "";
     const ref = "HEAD";
 
+    if (prerelease && !githubSha) {
+      const errorMessage =
+        "Prerelease is enabled but GITHUB_SHA environment variable is not available. This is required for prerelease tags.";
+      coreService.setFailed(errorMessage);
+      return;
+    }
+
     // Log context information for debugging
     coreService.info(`Working with local git repository`);
     coreService.info(`Commit ref: ${ref}`);
     coreService.info(`Last tag input: ${lastTag || "undefined"}`);
+    coreService.info(`Max tags limit: ${maxTags}`);
+    coreService.info(`Prerelease: ${prerelease}`);
+    coreService.info(`GitHub SHA: ${githubSha || "undefined"}`);
 
     const gitService = new LocalGitService();
     const commitAnalyzer = new ConventionalCommitAnalyzer();
@@ -261,7 +291,13 @@ export async function run(): Promise<void> {
     await gitService.testConnection();
     coreService.info("Git repository connection successful");
 
-    const newTag = await tagIncrementer.incrementTag(lastTag || undefined, ref);
+    const newTag = await tagIncrementer.incrementTag(
+      lastTag || undefined,
+      ref,
+      maxTags,
+      prerelease,
+      githubSha
+    );
 
     coreService.info(`Process completed successfully. New tag: ${newTag}`);
     coreService.setOutput("new-tag", newTag);