fix(tsdown-plugin): install typescript so the lib preset's declarations build

.changeset/tsdown-plugin-typescript.md

@@ -0,0 +1,5 @@
+---
+"@rrlab/tsdown-plugin": patch
+---
+
+`rr plugins add tsdown` adds `typescript` as a dev dependency, which tsdown needs to write the `lib` preset's declarations, unless the package already has it in `dependencies` or `devDependencies`. Before, `rr pack` failed with "TypeScript is not installed" in a project without the ts plugin. `rr plugins remove tsdown` keeps `typescript`.

run-run/tsdown-plugin/README.md

@@ -8,14 +8,14 @@
 rr plugins add tsdown
 ```
 
-`rr plugins add` installs `@rrlab/tsdown-plugin` and adds `tsdown` as a dev dependency. Once you confirm, it writes a `tsdown.config.ts` that calls a helper from [`@rrlab/tsdown-config`](https://www.npmjs.com/package/@rrlab/tsdown-config), for the kind of build you pick:
+`rr plugins add` installs `@rrlab/tsdown-plugin` and adds `tsdown` as a dev dependency. It adds `typescript` too, which tsdown needs to write declarations, unless the package already has it in `dependencies` or `devDependencies`. Once you confirm, it writes a `tsdown.config.ts` that calls a helper from [`@rrlab/tsdown-config`](https://www.npmjs.com/package/@rrlab/tsdown-config), for the kind of build you pick:
 
 - `lib`: a library, with declarations and the entry `src/index.ts`. It is the default.
 - `bin`: a CLI or Node binary, with the entry `src/run.ts`.
 
 If a `tsdown.config.*` already exists, you choose to patch it, keep it or overwrite it. Patching turns a default export that calls `defineConfig()` from `tsdown`, or either helper, into a call to the helper you picked, and keeps its options. It refuses any other shape.
 
-It needs `@rrlab/cli` and tsdown 0.22 or later.
+It needs `@rrlab/cli`, tsdown 0.22 or later and, to write declarations, TypeScript 5 or later.
 
 ## What it provides
 
@@ -43,7 +43,7 @@ Pass tsdown options to the helper to override its defaults, such as `defineLibCo
 rr plugins remove tsdown
 ```
 
-It removes `tsdown` and `@rrlab/tsdown-config` from `package.json`. If `tsdown.config.*` is the file it wrote, it deletes it; if you passed options to the helper, it rewrites the file to `defineConfig()` from `tsdown` and keeps them; any other config is left alone. Then it drops `tsdown()` from `run-run.config.{ts,mts}`.
+It removes `tsdown` and `@rrlab/tsdown-config` from `package.json`, and keeps `typescript`, which the project or another plugin may use. If `tsdown.config.*` is the file it wrote, it deletes it; if you passed options to the helper, it rewrites the file to `defineConfig()` from `tsdown` and keeps them; any other config is left alone. Then it drops `tsdown()` from `run-run.config.{ts,mts}`.
 
 ## License
 

run-run/tsdown-plugin/package.json

@@ -46,13 +46,20 @@
   },
   "peerDependencies": {
     "@rrlab/cli": "workspace:^",
-    "tsdown": ">=0.22.0"
+    "tsdown": ">=0.22.0",
+    "typescript": ">=5.0.0"
+  },
+  "peerDependenciesMeta": {
+    "typescript": {
+      "optional": true
+    }
   },
   "devDependencies": {
     "@rrlab/cli": "workspace:*",
     "@rrlab/tsdown-config": "workspace:^",
     "@types/semver": "^7.7.1",
     "semver": "^7.8.1",
-    "tsdown": "0.22.0"
+    "tsdown": "0.22.0",
+    "typescript": "6.0.3"
   }
 }

run-run/tsdown-plugin/src/__tests__/install.test.ts

@@ -4,7 +4,7 @@ import path from "node:path";
 import { type ClackPrompts, type InstallContext, ReleaseService, type UninstallContext } from "@rrlab/cli/plugin";
 import type { Pkg, ShellService } from "@variablelab/clibuddy";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
-import { install, uninstall } from "../index.ts";
+import { install, TOOL_VERSIONS, uninstall } from "../index.ts";
 
 let tmpDir: string;
 
@@ -16,12 +16,16 @@ afterEach(async () => {
   await fs.rm(tmpDir, { recursive: true, force: true });
 });
 
+function appPkg(packageJson: Pkg["packageJson"] = {}): Pkg {
+  return { dirPath: tmpDir, packageJson } as Pkg;
+}
+
 function installCtx(overrides: Partial<InstallContext> = {}): InstallContext {
   return {
     shell: {} as ShellService,
     // biome-ignore lint/suspicious/noExplicitAny: minimal stub for the test boundary
     logger: {} as any,
-    appPkg: { dirPath: tmpDir } as Pkg,
+    appPkg: appPkg(),
     prompts: stubPrompts(),
     flags: { force: false, yes: true, nonInteractive: true },
     release: new ReleaseService(undefined),
@@ -34,7 +38,7 @@ function uninstallCtx(overrides: Partial<UninstallContext> = {}): UninstallConte
     shell: {} as ShellService,
     // biome-ignore lint/suspicious/noExplicitAny: minimal stub
     logger: {} as any,
-    appPkg: { dirPath: tmpDir } as Pkg,
+    appPkg: appPkg(),
     prompts: stubPrompts(),
     flags: { yes: true, nonInteractive: true },
     ...overrides,
@@ -57,6 +61,7 @@ describe("@rrlab/tsdown-plugin install()", () => {
       const result = await install(installCtx());
       expect(result.devDependencies).toEqual({
         tsdown: expect.stringMatching(/\^?\d/),
+        typescript: TOOL_VERSIONS.typescript.install,
         "@rrlab/tsdown-config": "latest",
       });
       expect(result.files).toHaveLength(1);
@@ -67,14 +72,17 @@ describe("@rrlab/tsdown-plugin install()", () => {
       expect(op.content).toContain("export default defineLibConfig();");
     });
 
-    it("skips (only emits tsdown dep) when a config file already exists", async () => {
+    it("skips (only emits the tool deps) when a config file already exists", async () => {
       // Under --yes, we don't silently rewrite user code.
       await fs.writeFile(
         path.join(tmpDir, "tsdown.config.ts"),
         'import { defineConfig } from "tsdown";\nexport default defineConfig({});\n',
       );
       const result = await install(installCtx());
-      expect(result.devDependencies).toEqual({ tsdown: expect.any(String) });
+      expect(result.devDependencies).toEqual({
+        tsdown: expect.any(String),
+        typescript: TOOL_VERSIONS.typescript.install,
+      });
       expect(result.files).toBeUndefined();
     });
   });
@@ -89,7 +97,10 @@ describe("@rrlab/tsdown-plugin install()", () => {
         }),
       );
       expect(confirm).toHaveBeenCalledOnce();
-      expect(result.devDependencies).toEqual({ tsdown: expect.any(String) });
+      expect(result.devDependencies).toEqual({
+        tsdown: expect.any(String),
+        typescript: TOOL_VERSIONS.typescript.install,
+      });
       expect(result.files).toBeUndefined();
     });
 
@@ -183,7 +194,10 @@ describe("@rrlab/tsdown-plugin install()", () => {
         }),
       );
       expect(result.files).toBeUndefined();
-      expect(result.devDependencies).toEqual({ tsdown: expect.any(String) });
+      expect(result.devDependencies).toEqual({
+        tsdown: expect.any(String),
+        typescript: TOOL_VERSIONS.typescript.install,
+      });
     });
   });
 
@@ -223,6 +237,29 @@ describe("@rrlab/tsdown-plugin install()", () => {
     });
   });
 
+  describe("typescript (the lib preset's declarations need it)", () => {
+    it.each([
+      ["dependencies", { dependencies: { typescript: "^7.0.2" } }],
+      ["devDependencies", { devDependencies: { typescript: "~5.9.0" } }],
+    ])("leaves typescript out when the package already has it in %s", async (_field, packageJson) => {
+      const result = await install(installCtx({ appPkg: appPkg(packageJson) }));
+      expect(result.devDependencies).not.toHaveProperty("typescript");
+      expect(result.devDependencies).toHaveProperty("tsdown");
+    });
+
+    it("leaves typescript out on the skip path when the package already has it", async () => {
+      await fs.writeFile(path.join(tmpDir, "tsdown.config.ts"), "// custom\n");
+      const result = await install(installCtx({ appPkg: appPkg({ devDependencies: { typescript: "~5.9.0" } }) }));
+      expect(result.devDependencies).toEqual({ tsdown: expect.any(String) });
+    });
+
+    it("still adds typescript when the package only declares it as a peer", async () => {
+      // A peer isn't installed locally, and tsdown needs typescript installed to write declarations.
+      const result = await install(installCtx({ appPkg: appPkg({ peerDependencies: { typescript: ">=5.0.0" } }) }));
+      expect(result.devDependencies?.typescript).toBe(TOOL_VERSIONS.typescript.install);
+    });
+  });
+
   describe("release-driven sibling resolution", () => {
     it("threads ctx.release.resolve into @rrlab/tsdown-config's install spec", async () => {
       const release = new ReleaseService("pr-226", { fetcher: async () => new Response("{}", { status: 200 }) });

run-run/tsdown-plugin/src/index.ts

@@ -53,6 +53,20 @@ export class TsdownService extends ToolService {
   }
 }
 
+/**
+ * tsdown needs `typescript` installed to write declarations (the `lib`
+ * preset's `dts: true`, or a `types` entry in package.json), but takes it only
+ * as an optional peer. A package that already installs it (`dependencies` or
+ * `devDependencies`; a peer alone isn't installed) keeps the range it has.
+ */
+function toolDependencies(pkg: InstallContext["appPkg"]): Record<string, string> {
+  const { dependencies, devDependencies } = pkg.packageJson;
+  const installsTypescript = [dependencies, devDependencies].some((deps) => !!deps && "typescript" in deps);
+  return installsTypescript
+    ? { tsdown: TOOL_VERSIONS.tsdown.install }
+    : { tsdown: TOOL_VERSIONS.tsdown.install, typescript: TOOL_VERSIONS.typescript.install };
+}
+
 export async function install(ctx: InstallContext): Promise<InstallResult> {
   const existingPath = await findExistingConfig(ctx.appPkg.dirPath);
   const action = await decideScaffold(ctx, {
@@ -63,7 +77,7 @@ export async function install(ctx: InstallContext): Promise<InstallResult> {
   });
 
   if (action === "skip") {
-    return { devDependencies: { tsdown: TOOL_VERSIONS.tsdown.install } };
+    return { devDependencies: toolDependencies(ctx.appPkg) };
   }
 
   const preset = await pickPreset(ctx, {
@@ -74,7 +88,7 @@ export async function install(ctx: InstallContext): Promise<InstallResult> {
   const { factory } = PRESETS[preset];
 
   const devDependencies: Record<string, string> = {
-    tsdown: TOOL_VERSIONS.tsdown.install,
+    ...toolDependencies(ctx.appPkg),
     [CONFIG_PKG]: await ctx.release.resolve(CONFIG_PKG),
   };
 
@@ -108,6 +122,7 @@ export async function install(ctx: InstallContext): Promise<InstallResult> {
 }
 
 export async function uninstall(ctx: UninstallContext): Promise<UninstallResult> {
+  // `typescript` stays: the project or another plugin (ts, astro) may use it.
   const removeDependencies = ["tsdown", CONFIG_PKG];
   const existingPath = await findExistingConfig(ctx.appPkg.dirPath);
   if (!existingPath) return { removeDependencies };

run-run/tsdown-plugin/src/tool-versions.ts

@@ -1,3 +1,8 @@
 export const TOOL_VERSIONS = {
+  // `install` is the prescriptive pin used by `rr plugins add`'s nypm call.
+  // The looser contracts live in package.json#peerDependencies. typescript
+  // matches the ts and astro plugins' pin, so adding them in either order
+  // never leaves conflicting ranges.
   tsdown: { install: "^0.22.0" },
+  typescript: { install: "^6.0.0" },
 } as const;