ci: test React 15

.github/workflows/test.yml

@@ -31,6 +31,7 @@ jobs:
       fail-fast: false
       matrix:
         react:
+          - 15
           - 16
           - 17
           - 18
@@ -49,11 +50,17 @@ jobs:
       - name: Install legacy testing-library
         if: ${{ startsWith(matrix.react, '16') || startsWith(matrix.react, '17') }}
         run: pnpm add -D @testing-library/react@12.1.4
-      - name: Install legacy types
+      - name: Install legacy React types
         if: ${{ startsWith(matrix.react, '16') || startsWith(matrix.react, '17') || startsWith(matrix.react, '18')  }}
         run: pnpm add -D @types/react@${{ matrix.react }} @types/react-dom@${{ matrix.react }}
-      - name: Test ${{ matrix.react }} ${{ matrix.devtools-skip }}
-        run: |
-          pnpm add -D react@${{ matrix.react }} react-dom@${{ matrix.react }}
-          pnpm test
-          pnpm tsc
+      - name: Install ${{ matrix.react }}
+        run: pnpm add -D react@${{ matrix.react }} react-dom@${{ matrix.react }}
+      - name: Validate types
+        run:  pnpm tsc
+      - name: Test React 15
+        # Hooks are not supported in React 15, so skip testing it
+        if: ${{ startsWith(matrix.react, '15') }}
+        run:  pnpm vitest InView observe setup
+      - name: Test React
+        if: ${{ !startsWith(matrix.react, '5') }}
+        run:  pnpm test

src/__tests__/InView.test.tsx

@@ -57,7 +57,7 @@ test("Should handle initialInView", () => {
   const cb = vi.fn();
   render(
     <InView initialInView onChange={cb}>
-      {({ inView }) => `InView: ${inView}`}
+      {({ inView }) => <span>InView: {inView.toString()}</span>}
     </InView>,
   );
   screen.getByText("InView: true");

src/test-utils.ts

@@ -6,6 +6,7 @@ declare global {
 }
 
 const act =
+  // @ts-expect-error - Older versions of React don't have the `act` method, so TypeScript will complain about it
   typeof React.act === "function" ? React.act : DeprecatedReactTestUtils.act;
 
 type Item = {