feat(completion-hint): Add a hint prompting the user to add completion to the shell

.changeset/completion-login-hint.md

@@ -0,0 +1,5 @@
+---
+"@bunny.net/cli": minor
+---
+
+feat(login): `bunny login` now ends with a shell-specific tip for enabling tab completion (`bunny completion >> ~/.zshrc` style for zsh/bash, a lazy-loaded completions file for fish)

packages/cli/README.md

@@ -1264,12 +1264,20 @@ The method is case-insensitive (`get` and `GET` both work). Paths are relative t
 
 ### `bunny completion`
 
-Generate a shell completion script. Add the output to your shell profile to enable tab completion.
+Generate a shell completion script. Add the output to your shell profile to enable tab completion:
 
 ```bash
-bunny completion >> ~/.zshrc
+bunny completion >> ~/.zshrc # zsh; use ~/.bashrc for bash
 ```
 
+Fish loads completion files from its own directory:
+
+```bash
+mkdir -p ~/.config/fish/completions && bunny completion > ~/.config/fish/completions/bunny.fish
+```
+
+After `bunny login` succeeds, it prints the exact line for your shell.
+
 ## Global Options
 
 | Flag        | Alias | Description                                                  | Default   |

packages/cli/src/commands/auth/login.ts

@@ -18,6 +18,7 @@ import {
   readPassword,
   spinner,
 } from "../../core/ui.ts";
+import { hintShellCompletion } from "../completion/hint.ts";
 import { offerGlobalSkillInstall } from "../skills/offer.ts";
 
 const DASHBOARD_URL =
@@ -307,5 +308,6 @@ export const authLoginCommand = defineCommand<{
     }
 
     await offerGlobalSkillInstall(output, installSkill);
+    hintShellCompletion(output);
   },
 });

packages/cli/src/commands/completion/hint.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, test } from "bun:test";
+import { completionHint } from "./hint.ts";
+
+describe("completionHint", () => {
+  test("names the rc file and line for zsh, bash, and fish", () => {
+    expect(completionHint("/bin/zsh")).toBe(
+      "Tip: enable shell completions with: `bunny completion >> ~/.zshrc`.",
+    );
+    expect(completionHint("/usr/local/bin/bash")).toBe(
+      "Tip: enable shell completions with: `bunny completion >> ~/.bashrc`.",
+    );
+    expect(completionHint("/usr/local/bin/fish")).toBe(
+      "Tip: enable fish completions with: `mkdir -p ~/.config/fish/completions && bunny completion > ~/.config/fish/completions/bunny.fish`.",
+    );
+  });
+
+  test("returns undefined for other or missing shells", () => {
+    for (const shell of ["/usr/bin/nu", ""]) {
+      expect(completionHint(shell)).toBeUndefined();
+    }
+  });
+});

packages/cli/src/commands/completion/hint.ts

@@ -0,0 +1,31 @@
+import { basename } from "node:path";
+import { logger } from "../../core/logger.ts";
+
+const SHELL_HINTS: Record<string, string> = {
+  zsh: "Tip: enable shell completions with: `bunny completion >> ~/.zshrc`.",
+  bash: "Tip: enable shell completions with: `bunny completion >> ~/.bashrc`.",
+  // Fish lazy-loads completion files from this directory. Alternative would be: appending it to ~/.config/fish/config.fish.
+  fish: "Tip: enable fish completions with: `mkdir -p ~/.config/fish/completions && bunny completion > ~/.config/fish/completions/bunny.fish`.",
+};
+
+/** The one-line completion tip for the given `$SHELL` value; `undefined` when the shell is unknown. */
+export function completionHint(shell: string): string | undefined {
+  return SHELL_HINTS[basename(shell)];
+}
+
+/** Passive one-line completion hint shown after `bunny login`; suppressed under `--output json` and for unknown shells. */
+export function hintShellCompletion(
+  output?: string,
+  shell: string | undefined = process.env.SHELL,
+): void {
+  if (output === "json") return;
+
+  if (!shell) return;
+
+  // yargs doesn't support fish shell completions yet until next release.
+  // Once https://github.com/yargs/yargs/pull/2569 is merged, remove this check.
+  if (shell.includes("fish")) return;
+
+  const hint = completionHint(shell);
+  if (hint) logger.dim(hint);
+}