Testing

Commands

npm test                          # vitest run, everything
npx vitest run src/               # unit tests only (skip ISO integration tests)
npx vitest run src/timing/        # a single directory
npx vitest run test/pspautotests/pspautotests.test.ts -t "test/name"   # one autotest

Run npm run typecheck to check types.

Unit tests

Unit tests live next to the code under src/. CPU tests write programs as u32 arrays directly into RAM at 0x08000000 and run the interpreter:

• Data addresses must be well past the program end (e.g. RAM + 100), or the program overwrites its own data.
• BEQ offsets are in words from (PC + 4), not bytes.

pspautotests (integration)

The pspautotests suite is real PSP test programs (compiled .prx files) that print expected output. The runner boots each .prx and compares its stdout text against a .expected file, line by line.

• Runner: test/pspautotests/run-autotest.ts + test/pspautotests/pspautotests.test.ts.
• GPU tests are in a separate file: test/pspautotests/pspautotests-gpu.test.ts.
• Test .prx files come from ppsspp-reference/pspautotests/tests/.
• Output is captured via kernel.stdoutBuffer and host0: file interception in hle-io.ts.

Because the comparison is textual (program output, not framebuffer pixels), rendering-internal changes like pixel byte order do not affect these tests.

Integration tests with ISOs

Some tests boot real ISOs from test/fixtures/. These are skipped by npx vitest run src/. Puzzle Bobble is a known-good reference game for sanity checks.

Headless diagnostics

The emulator core runs under Node, where there is no WebGL so the software rasterizer is used. Useful entry points:

npx tsx tools/boot-iso.ts <iso> <frames>   # boot for N frames, print diagnostics
npx tsx tools/game-diag.ts <iso>           # headless game diagnostics

A .pspstate save state exported from the browser can be restored headless and run forward. This is a reliable way to reproduce an in-game issue offline. See Storage & Save States.