feat(ts): add aptBase() factory for cross-toolchain apt sharing

Author: markovejnovic

dsls/harmont-ts/src/index.ts

@@ -21,4 +21,5 @@ export {
 } from "./triggers.js";
 export { pipeline, type PipelineIR, type PipelineOptions } from "./pipeline.js";
 export { target, clearTargetCache } from "./target.js";
+export { aptBase } from "./toolchains/shared.js";
 export { renderEnvelope, type PipelineDefinition } from "./envelope.js";

dsls/harmont-ts/src/toolchains/shared.ts

@@ -12,6 +12,17 @@ export function nodeInstallCmd(version: string): string {
   return `curl -fsSL https://deb.nodesource.com/setup_${major}.x | bash - && apt-get install -y nodejs`;
 }
 
+export function aptBase(opts: {
+  packages: readonly string[];
+  image?: string;
+  label?: string;
+}): Step {
+  return scratch({ image: opts.image }).sh(aptInstallCmd(opts.packages), {
+    label: opts.label ?? ":apt: base",
+    cache: ttl(APT_TTL_SECONDS),
+  });
+}
+
 export function makeInstallChain(opts: {
   aptPackages: readonly string[];
   installCmd: string;

dsls/harmont-ts/tests/toolchains/shared.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, it } from "vitest";
+import { aptBase } from "../../src/toolchains/shared.js";
+import { rust } from "../../src/toolchains/rust.js";
+import { uv } from "../../src/toolchains/py/uv.js";
+import { pipeline } from "../../src/pipeline.js";
+
+describe("aptBase", () => {
+  it("creates a step with apt-get install", () => {
+    const base = aptBase({ packages: ["curl", "ca-certificates"] });
+    expect(base._cmd).toContain(
+      "apt-get update && apt-get install -y curl ca-certificates",
+    );
+  });
+
+  it("default label is :apt: base", () => {
+    const base = aptBase({ packages: ["curl"] });
+    expect(base._label).toBe(":apt: base");
+  });
+
+  it("accepts custom label", () => {
+    const base = aptBase({ packages: ["curl"], label: ":lock: deps" });
+    expect(base._label).toBe(":lock: deps");
+  });
+
+  it("shared across rust and python toolchains", () => {
+    const base = aptBase({
+      packages: [
+        "curl",
+        "ca-certificates",
+        "build-essential",
+        "pkg-config",
+        "libssl-dev",
+        "python3",
+        "python3-venv",
+      ],
+    });
+    const r = rust({ base });
+    const p = uv({ path: "dsls/harmont-py", base });
+    const ir = pipeline(r.build(), p.test(), { defaultImage: "ubuntu:24.04" });
+    const cmds = ir.graph.nodes.map(
+      (n: { step: { cmd: string } }) => n.step.cmd,
+    );
+    const aptSteps = cmds.filter((c: string) => c.includes("apt-get install"));
+    expect(aptSteps).toHaveLength(1);
+  });
+});