Include target stack for Heroku builds

README.md

@@ -12,7 +12,7 @@ Generate build information for tracking deployments.
 - **Clock** - includes the build time
 - **User** - includes the identity of the user
 - **Git** - includes the commit the build was based on and a summary of any changes from it
-- **Heroku** - includes the fact that it was built in Heroku and the commit it was based on
+- **Heroku** - includes the fact that it was built in Heroku, for which stack and from which commit
 - **GitHub Actions** - includes the build number and URL
 - **CircleCI** - includes the build number and URL
 - **Netlify** - includes the build number and URL

src/sources/heroku.test.ts

@@ -15,9 +15,9 @@ describe("Heroku", () => {
 		expect(heroku.applies()).to.equal(false);
 	});
 
-	it("exposes the source version", () => {
-		const heroku = new Heroku({ SOURCE_VERSION: "abc1234" });
+	it("exposes the source version and stack", () => {
+		const heroku = new Heroku({ SOURCE_VERSION: "abc1234", STACK: "heroku-22" });
 
-		expect(heroku.lines()).to.deep.equal(["In: Heroku", "From: abc1234"]);
+		expect(heroku.lines()).to.deep.equal(["In: Heroku", "For: heroku-22", "From: abc1234"]);
 	});
 });

src/sources/heroku.ts

@@ -8,6 +8,6 @@ export default class Heroku extends Env implements Source {
 	}
 
 	lines(): string[] {
-		return ["In: Heroku", `From: ${this.env["SOURCE_VERSION"]}`];
+		return ["In: Heroku", `For: ${this.env["STACK"]}`, `From: ${this.env["SOURCE_VERSION"]}`];
 	}
 }