refactor: tighten the tool map types

src/cli/command/install-tool.ts

@@ -2,7 +2,7 @@ import { isNonEmptyStringAndNotWhitespace } from '@sindresorhus/is';
 import { Command, Option } from 'clipanion';
 import prettyMilliseconds from 'pretty-ms';
 import { installTool, resolveVersion } from '../install-tool/index.ts';
-import { DeprecatedTools, ResolverMap } from '../tools/index.ts';
+import { DeprecatedTools, ResolverMap, getToolType } from '../tools/index.ts';
 import type { InstallToolType } from '../utils';
 import { MissingVersion } from '../utils/codes.ts';
 import { logger } from '../utils/index.ts';
@@ -46,14 +46,14 @@ export class InstallToolCommand extends Command {
 
     let version = this.version?.replace(/^v/, ''); // trim optional 'v' prefix
 
-    let type = DeprecatedTools[this.name];
+    let type = getToolType(DeprecatedTools, this.name);
 
     if (type) {
       logger.warn(
         `The 'install-tool ${this.name}' command is deprecated. Please use the 'install-${type} ${this.name}'.`,
       );
     } else {
-      type = ResolverMap[this.name] ?? this.type;
+      type = getToolType(ResolverMap, this.name) ?? this.type;
     }
 
     if (!isNonEmptyStringAndNotWhitespace(version)) {

src/cli/command/uninstall-tool.ts

@@ -2,7 +2,7 @@ import { isNonEmptyStringAndNotWhitespace } from '@sindresorhus/is';
 import { Command, Option } from 'clipanion';
 import prettyMilliseconds from 'pretty-ms';
 import { uninstallTool } from '../install-tool/index.ts';
-import { ResolverMap } from '../tools/index.ts';
+import { ResolverMap, getToolType } from '../tools/index.ts';
 import type { InstallToolType } from '../utils';
 import { MissingVersion } from '../utils/codes.ts';
 import { logger } from '../utils/index.ts';
@@ -55,7 +55,7 @@ export class UninstallToolCommand extends Command {
 
     let version = this.version;
 
-    const type = ResolverMap[tool] ?? this.type;
+    const type = getToolType(ResolverMap, tool) ?? this.type;
 
     if (!isNonEmptyStringAndNotWhitespace(version) && !all) {
       logger.error(`No version found for ${tool}`);

src/cli/install-tool/index.ts

@@ -39,7 +39,7 @@ import { CabalInstallService } from '../tools/haskell/cabal.ts';
 import { GhcInstallService } from '../tools/haskell/ghc.ts';
 import { HelmInstallService } from '../tools/helm.ts';
 import { HelmfileInstallService } from '../tools/helmfile.ts';
-import { ResolverMap } from '../tools/index.ts';
+import { ResolverMap, getToolType } from '../tools/index.ts';
 import {
   AndroidSdkCmdlineToolsInstallService,
   AndroidSdkCmdlineToolsVersionResolver,
@@ -332,7 +332,7 @@ export async function installTool(
               // some pip packages may not have a `--version` flag
               await super.test(version);
             } catch (err) {
-              if (ResolverMap[tool] === 'pip') {
+              if (getToolType(ResolverMap, tool) === 'pip') {
                 // those tools are known and should work
                 throw err;
               }

src/cli/tools/index.spec.ts

@@ -0,0 +1,24 @@
+import { describe, expect, test } from 'vitest';
+import { getToolType } from './index.ts';
+
+describe('cli/tools/index', () => {
+  describe('getToolType', () => {
+    const map = { poetry: 'pip', pnpm: 'npm' } as const;
+
+    test('returns the type of a mapped tool', () => {
+      expect(getToolType(map, 'poetry')).toBe('pip');
+      expect(getToolType(map, 'pnpm')).toBe('npm');
+    });
+
+    test('returns undefined for an unknown tool', () => {
+      expect(getToolType(map, 'unknown')).toBeUndefined();
+    });
+
+    test.each(['constructor', 'toString', '__proto__'])(
+      'returns undefined for the prototype key %s',
+      (name) => {
+        expect(getToolType(map, name)).toBeUndefined();
+      },
+    );
+  });
+});

src/cli/tools/index.ts

@@ -67,7 +67,7 @@ export const NoInitTools = [
  * Tools in this map are implicit mapped from `install-tool` to `install-<type>`.
  * So no need for an extra install service.
  */
-export const ResolverMap: Record<string, InstallToolType | undefined> = {
+export const ResolverMap: Record<string, InstallToolType> = {
   bundler: 'gem',
   checkov: 'pip',
   copier: 'pip',
@@ -87,7 +87,21 @@ export const ResolverMap: Record<string, InstallToolType | undefined> = {
  * This tools are deprecated and should not be used anymore via `install-tool`.
  * They are implicit mapped from `install-tool` to `install-<type>`.
  */
-export const DeprecatedTools: Record<string, InstallToolType | undefined> = {
+export const DeprecatedTools: Record<string, InstallToolType> = {
   bower: 'npm',
   lerna: 'npm',
 };
+
+/**
+ * Looks up the install type of a tool in the given map.
+ * Only own keys resolve, so names like `constructor` never match.
+ * @param map - tool to install type map
+ * @param name - tool name
+ * @returns the mapped install type or `undefined`
+ */
+export function getToolType(
+  map: Record<string, InstallToolType>,
+  name: string,
+): InstallToolType | undefined {
+  return Object.hasOwn(map, name) ? map[name] : undefined;
+}