Multi-Mode Config

Run one suite across several runtimes by declaring modes. This config builds for WASI and Node bindings by default, and keeps a headless browser mode and an esm-bindings mode available on demand.

{
  "$schema": "node_modules/as-test/as-test.config.schema.json",
  "input": ["assembly/__tests__/**/*.spec.ts"],
  "output": ".as-test/",
  "buildOptions": { "target": "wasi" },
  "runOptions": {
    "runtime": { "cmd": "node ./.as-test/runners/default.wasi.js" }
  },
  "modes": {
    "node:wasi": {
      "buildOptions": { "target": "wasi" },
      "runOptions": { "runtime": { "cmd": "node ./.as-test/runners/default.wasi.js" } }
    },
    "node:bindings": {
      "buildOptions": { "target": "bindings" },
      "runOptions": { "runtime": { "cmd": "node ./.as-test/runners/default.bindings.js" } }
    },
    "node:bindings:esm": {
      "default": false,
      "buildOptions": { "target": "bindings", "args": ["--bindings esm"] },
      "input": ["assembly/__tests__/**/*.spec.ts", "!**/unmock.spec.ts"],
      "runOptions": { "runtime": { "cmd": "node ./.as-test/runners/default.bindings.js" } }
    },
    "chromium:headless": {
      "default": false,
      "buildOptions": { "target": "web" },
      "runOptions": {
        "runtime": {
          "cmd": "node ./.as-test/runners/default.web.js --headless",
          "browser": "chromium"
        }
      }
    }
  }
}

Run the defaults, or pick modes explicitly:

ast test                                       # default modes: node:wasi, node:bindings
ast test --mode node:bindings:esm,chromium:headless
ast test --mode node:wasi                      # just one

What's going on:

• default: false keeps node:bindings:esm and chromium:headless out of a bare ast test, but reachable via --mode.
• The esm mode declares --bindings esm, so as-test doesn't add --bindings raw. Its input excludes unmock.spec.ts because import-mock fallbacks can't run under esm bindings.
• Each mode's outputs are namespaced (.as-test/build/<mode>/…) so artifacts don't collide.

To add a standalone WASI engine, point a mode's runtime at its binary with the <file> placeholder:

"wasmtime": {
  "default": false,
  "buildOptions": { "target": "wasi" },
  "runOptions": { "runtime": { "cmd": "wasmtime run <file>" } }
}

See Multiple Runtimes for the full mode reference.