Fix/non strings (#867)

Resolves an issue whereby non-strings can be passed into the config switch detector.

Closes #866

.changeset/unlucky-dragons-fry.md

@@ -0,0 +1,5 @@
+---
+'simple-git': patch
+---
+
+Resolves an issue whereby non-strings can be passed into the config switch detector.

simple-git/src/lib/plugins/block-unsafe-operations-plugin.ts

@@ -3,8 +3,8 @@ import type { SimpleGitPlugin } from './simple-git-plugin';
 import { GitPluginError } from '../errors/git-plugin-error';
 import type { SimpleGitPluginConfig } from '../types';
 
-function isConfigSwitch(arg: string) {
-   return arg.trim().toLowerCase() === '-c';
+function isConfigSwitch(arg: string | unknown) {
+   return typeof arg === 'string' && arg.trim().toLowerCase() === '-c';
 }
 
 function preventProtocolOverride(arg: string, next: string) {

simple-git/test/integration/plugin.unsafe.spec.ts

@@ -13,6 +13,12 @@ describe('add', () => {
 
    beforeEach(async () => (context = await createTestContext()));
 
+   it('ignores non string arguments', async () => {
+      const { threw } = await promiseResult(newSimpleGit(context.root).raw([['init']] as any));
+
+      expect(threw).toBe(false);
+   });
+
    it('allows overriding protocol when opting in to unsafe practices', async () => {
       const { threw } = await promiseResult(
          newSimpleGit(context.root, { unsafe: { allowUnsafeProtocolOverride: true } }).raw(