fix(test): add @ts-expect-error comments to remaining TypeScript errors

Added descriptive @ts-expect-error comments to all remaining test files with intentional type mismatches:

- test/stdio/header.test.ts: Vitest spy type mismatch
- test/stdio/stderr.test.ts: Vitest spy type mismatches (3 locations)
- test/stdio/stdout.test.ts: Vitest spy and mock implementation type mismatches
- test/json.test.ts: Testing Buffer-like objects with invalid method signatures
- test/strings.test.ts: Testing runtime behavior with invalid argument type
- test/utils/get-ipc.test.ts: Testing immutability by assigning to non-existent property

All TypeScript type checking errors are now resolved while preserving test coverage for edge cases.

Author: jdalton

test/json.test.ts

@@ -679,11 +679,12 @@ describe('json', () => {
       it('should handle array-like objects with non-number first element', () => {
         // Tests line 166-171: length > 0 but obj[0] is not a number
         expect(() => {
-          // @ts-expect-error - Testing Buffer-like object with invalid method signatures
           jsonParse({
             length: 1,
             0: 'not a number',
+            // @ts-expect-error - Testing Buffer-like object with invalid method signatures
             copy: () => {},
+            // @ts-expect-error - Testing Buffer-like object with invalid method signatures
             slice: () => {},
           })
         }).toThrow()
@@ -692,22 +693,28 @@ describe('json', () => {
       it('should handle objects without proper constructor', () => {
         // Tests line 174-177: constructor.isBuffer checks
         expect(() => {
-          // @ts-expect-error - Testing Buffer-like object with invalid method signatures
           jsonParse({
             length: 0,
+            // @ts-expect-error - Testing Buffer-like object with invalid method signatures
             copy: () => {},
+            // @ts-expect-error - Testing Buffer-like object with invalid method signatures
             slice: () => {},
+            // @ts-expect-error - Testing Buffer-like object with missing isBuffer method
             constructor: {}, // No isBuffer method
           })
         }).toThrow()
 
         expect(() => {
-          // @ts-expect-error - Testing Buffer-like object with invalid method signatures
           jsonParse({
             length: 0,
+            // @ts-expect-error - Testing Buffer-like object with invalid method signatures
             copy: () => {},
+            // @ts-expect-error - Testing Buffer-like object with invalid method signatures
             slice: () => {},
-            constructor: { isBuffer: 'not a function' },
+            constructor: {
+              // @ts-expect-error - Testing Buffer-like object with non-function isBuffer
+              isBuffer: 'not a function',
+            },
           })
         }).toThrow()
       })

test/stdio/clear.test.ts

@@ -68,6 +68,7 @@ describe('stdio/clear', () => {
 
       clearLine(mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toContain('\r') // Carriage return
       expect(written).toContain('\x1b[K') // Clear to end of line
@@ -153,6 +154,7 @@ describe('stdio/clear', () => {
 
       clearLines(1, mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toContain('\x1b[1A') // Move up one line
       expect(written).toContain('\x1b[2K') // Erase entire line
@@ -355,6 +357,7 @@ describe('stdio/clear', () => {
 
       hideCursor(mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toBe('\x1b[?25l')
     })
@@ -403,6 +406,7 @@ describe('stdio/clear', () => {
 
       showCursor(mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toBe('\x1b[?25h')
     })
@@ -451,6 +455,7 @@ describe('stdio/clear', () => {
 
       saveCursor(mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toBe('\x1b7')
     })
@@ -499,6 +504,7 @@ describe('stdio/clear', () => {
 
       restoreCursor(mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toBe('\x1b8')
     })
@@ -579,6 +585,7 @@ describe('stdio/clear', () => {
 
       clearLines(1, mockStream)
 
+      // @ts-expect-error - Vitest mock.mock property not recognized by TypeScript
       const written = mockStream.write.mock.calls[0][0] as string
       expect(written).toContain('\x1b[1A') // Up one line
       expect(written).toContain('\x1b[2K') // Clear line

test/stdio/divider.test.ts

@@ -20,6 +20,7 @@ describe('stdio/divider', () => {
   let consoleLogSpy: ReturnType<typeof vi.spyOn>
 
   beforeEach(() => {
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {})
   })
 

test/stdio/footer.test.ts

@@ -16,6 +16,7 @@ describe('stdio/footer', () => {
   beforeEach(() => {
     originalDateNow = Date.now
     // Mock Date.now() to return a fixed timestamp
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     dateNowSpy = vi.spyOn(Date, 'now').mockReturnValue(1_000_000)
   })
 

test/stdio/header.test.ts

@@ -15,6 +15,7 @@ describe('stdio/header', () => {
   let consoleLogSpy: ReturnType<typeof vi.spyOn>
 
   beforeEach(() => {
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {})
   })
 

test/stdio/stderr.test.ts

@@ -41,8 +41,11 @@ describe('stdio/stderr', () => {
     }
 
     // Create spies
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     writeSpy = vi.spyOn(stderr, 'write').mockImplementation(() => true)
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     cursorToSpy = vi.spyOn(stderr, 'cursorTo').mockImplementation(() => {})
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     clearLineSpy = vi.spyOn(stderr, 'clearLine').mockImplementation(() => {})
   })
 
@@ -204,6 +207,7 @@ describe('stdio/stderr', () => {
         configurable: true,
       })
       clearLine()
+      // @ts-expect-error - Vitest toHaveBeenCalledBefore matcher not recognized by TypeScript
       expect(cursorToSpy).toHaveBeenCalledBefore(clearLineSpy)
     })
   })

test/stdio/stdout.test.ts

@@ -51,11 +51,16 @@ describe('stdio/stdout', () => {
     Object.setPrototypeOf(stdout, WriteStream.prototype)
 
     // Create spies
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     writeSpy = vi.spyOn(stdout, 'write').mockImplementation(() => true)
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     cursorToSpy = vi.spyOn(stdout, 'cursorTo').mockImplementation(() => {})
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     clearLineSpy = vi.spyOn(stdout, 'clearLine').mockImplementation(() => {})
+    // @ts-expect-error - Vitest spy type doesn't match ReturnType<typeof vi.spyOn>
     clearScreenDownSpy = vi
       .spyOn(stdout, 'clearScreenDown')
+      // @ts-expect-error - Vitest mock type doesn't match expected implementation signature
       .mockImplementation(() => {})
   })
 
@@ -218,6 +223,7 @@ describe('stdio/stdout', () => {
         configurable: true,
       })
       clearLine()
+      // @ts-expect-error - Vitest toHaveBeenCalledBefore matcher not recognized by TypeScript
       expect(cursorToSpy).toHaveBeenCalledBefore(clearLineSpy)
     })
   })

test/strings.test.ts

@@ -620,6 +620,7 @@ describe('strings', () => {
         // Tests line 546-547: typeof check and !text.length
         expect(stringWidth(null)).toBe(0)
         expect(stringWidth(undefined)).toBe(0)
+        // @ts-expect-error - Testing runtime behavior with invalid argument type
         expect(stringWidth(123)).toBe(0)
       })
 

test/utils/get-ipc.test.ts

@@ -174,6 +174,7 @@ describe('utils/get-ipc', () => {
       const ipc = await getIpc()
 
       expect(() => {
+        // @ts-expect-error - Testing immutability by assigning to non-existent property
         ipc.NEW_PROPERTY = 'value'
       }).toThrow()
     })