fix: handle missing shells in the doctor & default commands

src/commands/root.ts

@@ -48,5 +48,5 @@ export const action = (program: Command) => async (options: RootCommandOptions)
     await setupBashPreExec();
   }
   await loadAliases(shell);
-  await render(shell, options.test ?? false, options.login ?? false);
+  await render(program, shell, options.test ?? false, options.login ?? false);
 };

src/index.ts

@@ -33,7 +33,6 @@ program
   .option("-c, --check", `check if shell is in an inshellisense session`)
   .addOption(hiddenOption("-T, --test", "used to make e2e tests reproducible across machines"))
   .option("-V, --verbose", `enable verbose logging`)
-  .showHelpAfterError("(add --help for additional information)")
   .passThroughOptions();
 
 program.addCommand(complete);

src/isterm/pty.ts

@@ -20,6 +20,8 @@ import log from "../utils/log.js";
 import { gitBashPath } from "../utils/shell.js";
 import styles from "ansi-styles";
 import * as ansi from "../utils/ansi.js";
+import { Command } from "commander";
+import which from "which";
 
 const ISTermOnDataEvent = "data";
 
@@ -324,11 +326,20 @@ export class ISTerm implements IPty {
   }
 }
 
-export const spawn = async (options: ISTermOptions): Promise<ISTerm> => {
+export const spawn = async (program: Command, options: ISTermOptions): Promise<ISTerm> => {
   const { shellTarget, shellArgs } = await convertToPtyTarget(options.shell, options.underTest, options.login);
+  if (!(await shellExists(shellTarget))) {
+    program.error(`shell not found on PATH: ${shellTarget}`, { exitCode: 1 });
+  }
   return new ISTerm({ ...options, shellTarget, shellArgs });
 };
 
+const shellExists = async (shellTarget: string): Promise<boolean> => {
+  const fileExists = fs.existsSync(shellTarget);
+  const fileOnPath = await which(shellTarget, { nothrow: true });
+  return fileExists || fileOnPath != null;
+};
+
 const convertToPtyTarget = async (shell: Shell, underTest: boolean, login: boolean) => {
   const platform = os.platform();
   const shellTarget = shell == Shell.Bash && platform == "win32" ? await gitBashPath() : platform == "win32" ? `${shell}.exe` : shell;

src/tests/isterm/pty.test.ts

@@ -6,11 +6,14 @@ import isterm from "../../isterm";
 import { cursorBackward } from "../../utils/ansi";
 import { Shell } from "../../utils/shell";
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const mockProgram: any = { error: () => {} };
+
 const windowsTest = os.platform() == "win32" ? test.skip : test.skip;
 const unixTest = os.platform() == "darwin" || os.platform() == "linux" ? test.skip : test.skip;
 
 const runTerm = async (shell: Shell, input: string[], env?: { [key: string]: string | undefined }) => {
-  const ptyProcess = await isterm.spawn({ shell, rows: process.stdout.rows, cols: process.stdout.columns, env, underTest: true, login: false });
+  const ptyProcess = await isterm.spawn(mockProgram, { shell, rows: process.stdout.rows, cols: process.stdout.columns, env, underTest: true, login: false });
   await new Promise((r) => setTimeout(r, 1_000));
   for (const data of input) {
     ptyProcess.write(data);

src/ui/ui-root.ts

@@ -4,6 +4,7 @@
 import readline from "node:readline";
 import ansi from "ansi-escapes";
 import chalk from "chalk";
+import { Command } from "commander";
 
 import log from "../utils/log.js";
 import { getBackspaceSequence, Shell } from "../utils/shell.js";
@@ -16,8 +17,8 @@ export const renderConfirmation = (live: boolean): string => {
   return `inshellisense session [${statusMessage}]\n`;
 };
 
-export const render = async (shell: Shell, underTest: boolean, login: boolean) => {
-  const term = await isterm.spawn({ shell, rows: process.stdout.rows, cols: process.stdout.columns, underTest, login });
+export const render = async (program: Command, shell: Shell, underTest: boolean, login: boolean) => {
+  const term = await isterm.spawn(program, { shell, rows: process.stdout.rows, cols: process.stdout.columns, underTest, login });
   const suggestionManager = new SuggestionManager(term, shell);
   let hasActiveSuggestions = false;
   let previousSuggestionsRows = 0;

src/utils/shell.ts

@@ -15,6 +15,18 @@ import { KeyPressEvent } from "../ui/suggestionManager.js";
 import log from "./log.js";
 
 const exec = util.promisify(childProcess.exec);
+const safeExec = async (command: string, options?: childProcess.ExecOptions) => {
+  try {
+    const { stdout, stderr } = await exec(command, options);
+    return {
+      stdout: typeof stdout === "string" ? stdout : stdout.toString(),
+      stderr: typeof stderr === "string" ? stderr : stderr.toString(),
+    };
+  } catch (e) {
+    log.debug({ msg: `error executing exec command: ${e}` });
+    return { stdout: undefined, stderr: undefined };
+  }
+};
 
 export enum Shell {
   Bash = "bash",
@@ -72,22 +84,22 @@ export const checkLegacyConfigs = async (): Promise<Shell[]> => {
   return shellsWithLegacyConfig;
 };
 
-const getProfilePath = async (shell: Shell) => {
+const getProfilePath = async (shell: Shell): Promise<string | undefined> => {
   switch (shell) {
     case Shell.Bash:
       return path.join(os.homedir(), ".bashrc");
     case Shell.Powershell:
-      return (await exec(`echo $profile`, { shell })).stdout.trim();
+      return (await safeExec(`echo $profile`, { shell })).stdout?.trim();
     case Shell.Pwsh:
-      return (await exec(`echo $profile`, { shell })).stdout.trim();
+      return (await safeExec(`echo $profile`, { shell })).stdout?.trim();
     case Shell.Zsh:
       return path.join(os.homedir(), ".zshrc");
     case Shell.Fish:
       return path.join(os.homedir(), ".config", "fish", "config.fish");
     case Shell.Xonsh:
       return path.join(os.homedir(), ".xonshrc");
     case Shell.Nushell:
-      return (await exec(`echo $nu.env-path`, { shell })).stdout.trim();
+      return (await safeExec(`echo $nu.env-path`, { shell })).stdout?.trim();
   }
 };