cardano-wasm demo: test suites wired into CI

.changes/20260718_cardano_wasm_demo_tests.yml

@@ -0,0 +1,9 @@
+project: cardano-wasm
+
+pr: 1318
+
+kind:
+  - test
+
+description: |
+  Demo: elm-test suite and Node wasm API regression suite, both wired into the WASM CI workflow.

.github/workflows/haskell-wasm.yml

@@ -236,9 +236,16 @@ jobs:
     - name: Build wallet demo
       run: |
         cd cardano-wasm/demo
-        elm-format --validate src/
+        elm-format --validate src/ tests/
+        elm-test
         ./build.sh --wasm-dir ../lib-wrapper --out dist
 
+    - name: Demo wasm API regression tests
+      run: |
+        cd cardano-wasm/demo/tests/wasm
+        npm install
+        node api-regression.mjs
+
     - name: Upload wallet demo
       uses: actions/upload-artifact@v4
       with:

cardano-wasm/demo/.gitignore

@@ -1,2 +1,3 @@
 dist/
 elm-stuff/
+tests/wasm/node_modules/

cardano-wasm/demo/README.md

@@ -52,6 +52,7 @@ python3 -m http.server -d dist 8080     # any static server works
 ```
 src/        the Elm application
 web/        page shell, CSS, and the JS glue that drives the cardano-wasm API
+tests/      elm-test unit suite and the Node wasm API regression suite
 build.sh    compiles the Elm app and assembles a servable directory
 ```
 
@@ -61,6 +62,9 @@ from Elm over HTTPS.
 
 ## Development
 
-- Source is `elm-format`-canonical; CI validates it (`elm-format --validate src/`).
-- CI builds the demo in the *Haskell CI (WASM)* workflow and the GitHub Pages workflow
-  publishes the result.
+- Source is `elm-format`-canonical; CI validates it (`elm-format --validate src/ tests/`).
+- Unit tests for the pure core (bech32, ada ↔ lovelace, balance arithmetic): `elm-test`.
+- API regression tests against the built wasm library: see
+  [`tests/wasm/README.md`](tests/wasm/README.md).
+- CI runs all of the above in the *Haskell CI (WASM)* workflow and the GitHub Pages
+  workflow publishes the built demo.

cardano-wasm/demo/elm.json

@@ -21,7 +21,11 @@
         }
     },
     "test-dependencies": {
-        "direct": {},
-        "indirect": {}
+        "direct": {
+            "elm-explorations/test": "2.2.1"
+        },
+        "indirect": {
+            "elm/random": "1.0.0"
+        }
     }
 }