feat: support LiquidJS templates in strategy properties

Property values are now rendered through the template engine with the
same context available to version and tag templates. This allows
properties like:

  properties:
    previousVersion: "{{ commitInfo.previousSemVerReleaseVersion }}"
    baseVersion: "{{ commitInfo.previousSemVerReleaseVersion | semver_inc: 'minor' }}"

Static string values continue to work as before.

Closes #64

docs/configuration.md

@@ -87,12 +87,12 @@ output:
 
 Settings defined here are inherited by all strategies via deep merge (except `branchPrefixes`, which is only used at the top level).
 
-| Key              | Type                     | Default | Description                                              |
-| ---------------- | ------------------------ | ------- | -------------------------------------------------------- |
-| `branchPrefixes` | `string[]`               | `[]`    | Prefixes stripped from branch names before slugification |
-| `snapshot`       | `SnapshotConfig`         | `{}`    | Snapshot version generation settings                     |
-| `tags`           | `TagsConfig`             | `{}`    | Tag generation settings                                  |
-| `properties`     | `Record<string, string>` | `{}`    | Custom key-value pairs included in output                |
+| Key              | Type                     | Default | Description                                                                             |
+| ---------------- | ------------------------ | ------- | --------------------------------------------------------------------------------------- |
+| `branchPrefixes` | `string[]`               | `[]`    | Prefixes stripped from branch names before slugification                                |
+| `snapshot`       | `SnapshotConfig`         | `{}`    | Snapshot version generation settings                                                    |
+| `tags`           | `TagsConfig`             | `{}`    | Tag generation settings                                                                 |
+| `properties`     | `Record<string, string>` | `{}`    | Custom key-value pairs included in output (supports [LiquidJS templates](templates.md)) |
 
 ### SnapshotConfig
 
@@ -125,12 +125,12 @@ Each entry is a LiquidJS template. Empty results are filtered out, and duplicate
 
 Each strategy is an independent configuration that produces its own version string and tags. Strategies inherit from `defaults` via deep merge.
 
-| Key          | Type                     | Default | Description                                    |
-| ------------ | ------------------------ | ------- | ---------------------------------------------- |
-| `enabled`    | `boolean`                | `true`  | Whether this strategy is active                |
-| `snapshot`   | `SnapshotConfig`         | `{}`    | Snapshot settings (merged with defaults)       |
-| `tags`       | `TagsConfig`             | `{}`    | Tag generation settings (merged with defaults) |
-| `properties` | `Record<string, string>` | `{}`    | Custom key-value pairs included in output      |
+| Key          | Type                     | Default | Description                                                                             |
+| ------------ | ------------------------ | ------- | --------------------------------------------------------------------------------------- |
+| `enabled`    | `boolean`                | `true`  | Whether this strategy is active                                                         |
+| `snapshot`   | `SnapshotConfig`         | `{}`    | Snapshot settings (merged with defaults)                                                |
+| `tags`       | `TagsConfig`             | `{}`    | Tag generation settings (merged with defaults)                                          |
+| `properties` | `Record<string, string>` | `{}`    | Custom key-value pairs included in output (supports [LiquidJS templates](templates.md)) |
 
 ### OutputConfig
 

docs/templates.md

@@ -191,4 +191,5 @@ strategies:
         - "{% if versionInfo.isHighestSemVerReleaseVersion %}stable{% endif %}"
     properties:
       chartName: my-app
+      previousVersion: "{{ commitInfo.previousSemVerReleaseVersion }}"
 ```

src/version/versionStrategy.test.ts

@@ -150,6 +150,25 @@ describe("VersionStrategy", () => {
       );
       expect(result.customProp).toBe("value");
     });
+
+    it("should render template expressions in properties", () => {
+      const config = createStrategyConfig({
+        properties: {
+          commitSha: "{{ commitInfo.sha }}",
+          tagName: "{{ version }}",
+          static: "plain-value",
+        },
+      });
+      const strategy = new VersionStrategy("test", config);
+      const result = strategy.taggedVersionResult(
+        createContext({ isTaggedVersion: true }),
+        createCommitInfo({ sha: "abc123def456", tag: "build-123" }),
+        "build-123",
+      );
+      expect(result.commitSha).toBe("abc123def456");
+      expect(result.tagName).toBe("build-123");
+      expect(result.static).toBe("plain-value");
+    });
   });
 
   describe("semVerVersionResult", () => {
@@ -164,6 +183,24 @@ describe("VersionStrategy", () => {
       expect(result.version).toBe("1.2.3");
     });
 
+    it("should render template expressions in properties with semVer context", () => {
+      const config = createStrategyConfig({
+        properties: {
+          majorVersion: "{{ semVer.major }}",
+          previousRelease: "{{ commitInfo.previousSemVerReleaseVersion }}",
+        },
+      });
+      const strategy = new VersionStrategy("test", config);
+      const version = semver.parse("2.3.0")!;
+      const result = strategy.semVerVersionResult(
+        createContext({ isSemVerVersion: true }),
+        createCommitInfo({ tag: "v2.3.0" }),
+        version,
+      );
+      expect(result.majorVersion).toBe("2");
+      expect(result.previousRelease).toBe("1.0.0");
+    });
+
     it("should make semVer context available in tag templates", () => {
       const strategy = new VersionStrategy("test", createStrategyConfig());
       const version = semver.parse("2.3.0")!;
@@ -290,5 +327,22 @@ describe("VersionStrategy", () => {
       );
       expect(result.version).toEndWith("-SNAPSHOT");
     });
+
+    it("should render template expressions in properties with snapshot context", () => {
+      const config = createStrategyConfig({
+        properties: {
+          baseVersion:
+            "{{ commitInfo.previousSemVerReleaseVersion | semver_inc: 'minor' }}",
+          snapshotVersion: "{{ version }}",
+        },
+      });
+      const strategy = new VersionStrategy("test", config);
+      const result = strategy.snapshotVersionResult(
+        createContext({ isSnapshotVersion: true }),
+        createCommitInfo(),
+      );
+      expect(result.baseVersion).toBe("1.1.0");
+      expect(result.snapshotVersion).toBe("1.0.0-20240101120000.abc123def456");
+    });
   });
 });

src/version/versionStrategy.ts

@@ -27,13 +27,15 @@ export class VersionStrategy {
     commitInfo: CommitInfo,
     tag: string,
   ): StrategyVersion {
+    const tplContext = {
+      ...this.templateContext(context, commitInfo),
+      version: tag,
+    };
+
     return {
       version: tag,
-      tags: this.uniqueTags(this.config.tags.tagged, {
-        ...this.templateContext(context, commitInfo),
-        version: tag,
-      }),
-      ...this.config.properties,
+      tags: this.uniqueTags(this.config.tags.tagged, tplContext),
+      ...this.renderProperties(tplContext),
     };
   }
 
@@ -44,14 +46,16 @@ export class VersionStrategy {
   ): StrategyVersion {
     const stringVersion = semVerVersionString(version);
 
+    const tplContext = {
+      ...this.templateContext(context, commitInfo),
+      version: stringVersion,
+      semVer: version,
+    };
+
     return {
       version: stringVersion,
-      tags: this.uniqueTags(this.config.tags.semVer, {
-        ...this.templateContext(context, commitInfo),
-        version: stringVersion,
-        semVer: version,
-      }),
-      ...this.config.properties,
+      tags: this.uniqueTags(this.config.tags.semVer, tplContext),
+      ...this.renderProperties(tplContext),
     };
   }
 
@@ -99,17 +103,19 @@ export class VersionStrategy {
       },
     );
 
+    const snapshotTplContext = {
+      ...templateContext,
+      version,
+      prefix,
+      suffix,
+      branchIdentifier,
+      commitIdentifier,
+    };
+
     return {
       version: version,
-      tags: this.uniqueTags(this.config.tags.snapshot, {
-        ...templateContext,
-        version,
-        prefix,
-        suffix,
-        branchIdentifier,
-        commitIdentifier,
-      }),
-      ...this.config.properties,
+      tags: this.uniqueTags(this.config.tags.snapshot, snapshotTplContext),
+      ...this.renderProperties(snapshotTplContext),
     };
   }
 
@@ -125,6 +131,15 @@ export class VersionStrategy {
     };
   }
 
+  private renderProperties(context: any): Record<string, string> {
+    return Object.fromEntries(
+      Object.entries(this.config.properties).map(([key, value]) => [
+        key,
+        templateEngine.parseAndRenderSync(value, context),
+      ]),
+    );
+  }
+
   private uniqueTags(templates: string[], context: any) {
     if (!this.config.tags.enabled) {
       return [];