tests: one fixture for the note grammar, run by the core, the server and the web

The checklist grammar and the #tag rule are implemented three times (derive.rs,
checklist.py/tags.py, markdown.ts), and the tag colour twice (colors.ts,
DerivedTint.kt). Only Rust and Kotlin had tests. core/testdata/grammar.json now
holds one set of cases (task lines, rendered items, tags, standalone-tag lifts
and the tint hashes), and every suite reads it.

- web: vitest, a dev dependency approved for #5166, with `npm test`.
  grammar.test.ts runs the fixture, and titles.test.ts pins #5165's palette fix.
- ci.yml runs the web tests in the job the image build needs. desktop.yml's
  verify job runs them too, because the installers embed this frontend and
  can't see ci.yml's verdict (rule 177).
- core: derive.rs reads the fixture. server: tests/test_grammar_fixture.py.
- Android keeps its hand-written tint values; its doc now points at the fixture.

The server is expected red here, on purpose. tags.py only takes a tag after
whitespace and lets it start with a digit or `_`, while the core (the
definition) takes any non-tag boundary and needs a letter. So `(#todo)` is a
label on the phone and plain text on the server. The fix follows.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.forgejo/workflows/ci.yml

@@ -143,8 +143,12 @@ jobs:
             echo "build=true" >> $GITHUB_OUTPUT
           fi
 
+  # The web's whole verification: the type check, then its unit tests. Both in the
+  # job `build` already needs, so a red web test blocks the image like any other
+  # lane (rule 177). The unit tests arrived with #5166; before them the web copy of
+  # the note grammar, mirrored in Rust and Python, was guarded by nothing.
   typecheck:
-    name: TypeScript typecheck
+    name: Web typecheck and unit tests
     if: github.ref == 'refs/heads/dev' || github.ref == 'refs/heads/main'
     runs-on: python-ci
     container:
@@ -160,6 +164,10 @@ jobs:
         run: npx vue-tsc --noEmit
         working-directory: frontend
 
+      - name: Unit tests
+        run: npm test
+        working-directory: frontend
+
   lint:
     name: Python lint
     if: github.ref == 'refs/heads/dev' || github.ref == 'refs/heads/main'

.forgejo/workflows/desktop.yml

@@ -89,7 +89,7 @@ jobs:
   # bundling. No `always()` or `continue-on-error` anywhere on this path: a skipped
   # or failed verify must leave both publishers skipped.
   verify:
-    name: Clippy, tests and rustfmt
+    name: Web tests, clippy, Rust tests and rustfmt
     needs: [decide]
     if: needs.decide.outputs.build == 'true'
     runs-on: python-ci
@@ -105,6 +105,13 @@ jobs:
         run: npm ci && npm run build
         working-directory: frontend
 
+      # The web's unit tests, HERE as well as in ci.yml. The installers embed this
+      # frontend, and ci.yml's verdict is invisible to this workflow — run there only,
+      # a red web test would still let both installers publish (rule 177).
+      - name: Web unit tests
+        run: npm test
+        working-directory: frontend
+
       # --locked on the FIRST cargo invocation is the lockfile gate: it fails the
       # run if Cargo.toml and the committed Cargo.lock disagree, instead of silently
       # re-resolving (issue 2102). Both publishing jobs need this job, so neither

android/app/src/test/java/com/fabledsword/inkwell/ui/DerivedTintTest.kt

@@ -7,12 +7,10 @@ import org.junit.Test
 /**
  * Pins the derived-colour rule against `frontend/src/notes/colors.ts`.
  *
- * These are not tests of Kotlin — they are the ONE mechanical guard the mirrored pair
+ * These are not tests of Kotlin — they pin the pair. The web runs the same values
- * has. The web side is TypeScript with no test runner (its CI lane is `vue-tsc
+ * from `core/testdata/grammar.json` (`tint`) in `notes/grammar.test.ts`; this file
- * --noEmit` and nothing else), so if these values drift, nothing on that surface will
+ * writes them out by hand, so changing the hash or the key order means changing the
- * say so and a tag will simply be a different colour on the phone than in the browser.
+ * fixture and this file together, or one of the two suites goes red.
- * The same names and hashes are written into colors.ts as a comment; changing either
- * side means changing both and re-checking here.
  *
  * SMALLER SINCE M315. Half of what this file used to pin — the generated card fill, and
  * the resolution order that chose between a picked colour, a tag's and a generated one

core/src/local/derive.rs

@@ -770,4 +770,78 @@ mod tests {
         assert_eq!(touched, body);
         assert_eq!(extract_items(&touched), items);
     }
+
+    // ── the shared fixture ───────────────────────────────────────────────────
+    //
+    // core/testdata/grammar.json is the one set of cases the server (pytest), the web
+    // (vitest) and this file all run. The cases above stay as this file's own
+    // reasoning; these are the ones the other languages have agreed to.
+
+    fn fixture() -> serde_json::Value {
+        serde_json::from_str(include_str!("../../testdata/grammar.json"))
+            .expect("grammar.json parses")
+    }
+
+    fn strings(v: &serde_json::Value) -> Vec<String> {
+        v.as_array()
+            .expect("an array")
+            .iter()
+            .map(|s| s.as_str().expect("a string").to_string())
+            .collect()
+    }
+
+    #[test]
+    fn fixture_task_lines() {
+        for case in fixture()["task_lines"].as_array().unwrap() {
+            let line = case["line"].as_str().unwrap();
+            let got: Vec<(String, bool)> = extract_items(line)
+                .into_iter()
+                .map(|i| (i.text, i.checked))
+                .collect();
+            let want: Vec<(String, bool)> = match &case["item"] {
+                serde_json::Value::Null => Vec::new(),
+                item => vec![(
+                    item["text"].as_str().unwrap().to_string(),
+                    item["checked"].as_bool().unwrap(),
+                )],
+            };
+            assert_eq!(got, want, "line {line:?}");
+        }
+    }
+
+    #[test]
+    fn fixture_rendered_items() {
+        for case in fixture()["rendered_items"].as_array().unwrap() {
+            let text = case["text"].as_str().unwrap();
+            let checked = case["checked"].as_bool().unwrap();
+            assert_eq!(render_item(text, checked), case["line"].as_str().unwrap());
+        }
+    }
+
+    #[test]
+    fn fixture_tags() {
+        for case in fixture()["tags"].as_array().unwrap() {
+            let body = case["body"].as_str().unwrap();
+            assert_eq!(extract_tags(body), strings(&case["tags"]), "body {body:?}");
+        }
+    }
+
+    #[test]
+    fn fixture_lifts() {
+        for case in fixture()["lifts"].as_array().unwrap() {
+            let body = case["body"].as_str().unwrap();
+            let (standalone, inline, lifted) = lift_standalone_tags(body);
+            assert_eq!(
+                standalone,
+                strings(&case["standalone"]),
+                "standalone, body {body:?}"
+            );
+            assert_eq!(inline, strings(&case["inline"]), "inline, body {body:?}");
+            assert_eq!(
+                lifted,
+                case["lifted"].as_str().unwrap(),
+                "lifted, body {body:?}"
+            );
+        }
+    }
 }

core/testdata/grammar.json

@@ -0,0 +1,88 @@
+{
+  "_about": [
+    "The cases every implementation of the note grammar is tested against.",
+    "One file, read by four test suites: core (derive.rs), the server (checklist.py, tags.py), the web (markdown.ts, colors.ts) and, for the tint, Android (DerivedTint.kt, which pins the same values by hand).",
+    "A difference between any two implementations is a note that changes shape when it syncs. Add a case here, not to one suite.",
+    "Lives under core/ because core is the definition, and because core/ is in the desktop, Android and server file sets, so changing a case reruns every suite that reads it.",
+    "Tag cases are plain text on purpose. The web's renderer lets `code` and **bold** claim a `#` first, which the derivers do not; that is a rendering choice, not grammar, and is tested where it lives."
+  ],
+
+  "task_lines": [
+    { "line": "- [ ] milk", "item": { "checked": false, "text": "milk" } },
+    { "line": "- [x] milk", "item": { "checked": true, "text": "milk" } },
+    { "line": "- [X] milk", "item": { "checked": true, "text": "milk" } },
+    { "line": "* [ ] star bullet", "item": { "checked": false, "text": "star bullet" } },
+    { "line": "  - [ ] indented", "item": { "checked": false, "text": "indented" } },
+    { "line": "\t- [ ] tab indent", "item": { "checked": false, "text": "tab indent" } },
+    { "line": "-  [ ] two spaces after the bullet", "item": { "checked": false, "text": "two spaces after the bullet" } },
+    { "line": "- [ ]", "item": { "checked": false, "text": "" } },
+    { "line": "- [ ]   ", "item": { "checked": false, "text": "" } },
+    { "line": "- [ ] trailing space kept  ", "item": { "checked": false, "text": "trailing space kept  " } },
+    { "line": "- [ ]x", "item": null },
+    { "line": "-[ ] x", "item": null },
+    { "line": "+ [ ] plus bullet", "item": null },
+    { "line": "- [y] x", "item": null },
+    { "line": "- [  ] x", "item": null },
+    { "line": "text - [ ] x", "item": null },
+    { "line": "- milk", "item": null },
+    { "line": "", "item": null }
+  ],
+
+  "rendered_items": [
+    { "text": "milk", "checked": false, "line": "- [ ] milk" },
+    { "text": "milk", "checked": true, "line": "- [x] milk" },
+    { "text": "", "checked": false, "line": "- [ ]" },
+    { "text": "", "checked": true, "line": "- [x]" }
+  ],
+
+  "tags": [
+    { "body": "#todo buy milk", "tags": ["todo"] },
+    { "body": "buy #milk and #eggs", "tags": ["milk", "eggs"] },
+    { "body": "#Todo and #todo", "tags": ["Todo"] },
+    { "body": "line one\n#two", "tags": ["two"] },
+    { "body": "#tag, and #more.", "tags": ["tag", "more"] },
+    { "body": "#x-y_z9", "tags": ["x-y_z9"] },
+    { "body": "#café #über", "tags": ["café", "über"] },
+    { "body": "(#todo)", "tags": ["todo"] },
+    { "body": "end.#tag", "tags": ["tag"] },
+    { "body": "#tag#more", "tags": ["tag"] },
+    { "body": "a#b", "tags": [] },
+    { "body": "x-#tag", "tags": [] },
+    { "body": "##x", "tags": [] },
+    { "body": "#1st", "tags": [] },
+    { "body": "#2024", "tags": [] },
+    { "body": "#_x", "tags": [] },
+    { "body": "# heading", "tags": [] },
+    { "body": "see https://x.com/page#frag", "tags": [] },
+    { "body": "", "tags": [] }
+  ],
+
+  "lifts": [
+    { "body": "#todo\nreorganize the homepage", "standalone": ["todo"], "inline": [], "lifted": "reorganize the homepage" },
+    { "body": "buy milk #grocery", "standalone": [], "inline": ["grocery"], "lifted": "buy milk #grocery" },
+    { "body": "first\n\n#todo\n\nsecond", "standalone": ["todo"], "inline": [], "lifted": "first\n\nsecond" },
+    { "body": "#todo\ncall #todo later", "standalone": [], "inline": ["todo"], "lifted": "call #todo later" },
+    { "body": "#a #b", "standalone": [], "inline": ["a", "b"], "lifted": "#a #b" },
+    { "body": "```\n# comment #todo\n```", "standalone": [], "inline": ["todo"], "lifted": "```\n# comment #todo\n```" },
+    { "body": "(#todo)\nnotes", "standalone": [], "inline": ["todo"], "lifted": "(#todo)\nnotes" }
+  ],
+
+  "tint": {
+    "keys": ["red", "orange", "yellow", "green", "teal", "blue", "purple", "pink", "gray"],
+    "hashes": [
+      { "id": "00000000-0000-0000-0000-000000000000", "hash": 3192360657, "color": "purple" },
+      { "id": "11111111-1111-1111-1111-111111111111", "hash": 1031130113, "color": "blue" },
+      { "id": "6ba7b810-9dad-11d1-80b4-00c04fd430c8", "hash": 4043892016, "color": "orange" },
+      { "id": "f47ac10b-58cc-4372-a567-0e02b2c3d479", "hash": 1533351232, "color": "orange" }
+    ],
+    "names": [
+      { "name": "todo", "color": "pink" },
+      { "name": "grocery", "color": "blue" },
+      { "name": "work", "color": "green" },
+      { "name": "home", "color": "gray" },
+      { "name": "ideas", "color": "green" },
+      { "name": "reading", "color": "gray" },
+      { "name": "urgent", "color": "red" }
+    ]
+  }
+}

frontend/package-lock.json

@@ -19,6 +19,7 @@
         "tailwindcss": "^3.4.0",
         "typescript": "~5.5.0",
         "vite": "^5.4.0",
+        "vitest": "^3.2.7",
         "vue-tsc": "^2.1.0"
       }
     },
@@ -640,9 +641,6 @@
         "arm"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -657,9 +655,6 @@
         "arm"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -674,9 +669,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -691,9 +683,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -708,9 +697,6 @@
         "loong64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -725,9 +711,6 @@
         "loong64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -742,9 +725,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -759,9 +739,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -776,9 +753,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -793,9 +767,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -810,9 +781,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -827,9 +795,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -844,9 +809,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -937,6 +899,22 @@
         "win32"
       ]
     },
+    "node_modules/@types/chai": {
+      "version": "5.2.3",
+      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-5.2.3.tgz",
+      "integrity": "sha512-Mw558oeA9fFbv65/y4mHtXDs9bPnFMZAL/jxdPFUpOHHIXX91mcgEHbS5Lahr+pwZFR8A7GQleRWeI6cGFC2UA==",
+      "dev": true,
+      "dependencies": {
+        "@types/deep-eql": "*",
+        "assertion-error": "^2.0.1"
+      }
+    },
+    "node_modules/@types/deep-eql": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/@types/deep-eql/-/deep-eql-4.0.2.tgz",
+      "integrity": "sha512-c9h9dVVMigMPc4bwTvC5dxqtqJZwQPePsWjPlpSOnojbor6pGqdk541lfA7AqFQr5pB1BRdq0juY9db81BwyFw==",
+      "dev": true
+    },
     "node_modules/@types/estree": {
       "version": "1.0.9",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.9.tgz",
@@ -958,6 +936,123 @@
         "vue": "^3.2.25"
       }
     },
+    "node_modules/@vitest/expect": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-3.2.7.tgz",
+      "integrity": "sha512-E8eBXaKibuvH2pSZErOjdVb5vF4PbKYcrnluBTYxEk1l/VhhwZg1kZQsdtjq+CsF5CFydf2Rdkz7jDHKSisi3w==",
+      "dev": true,
+      "dependencies": {
+        "@types/chai": "^5.2.2",
+        "@vitest/spy": "3.2.7",
+        "@vitest/utils": "3.2.7",
+        "chai": "^5.2.0",
+        "tinyrainbow": "^2.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/mocker": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-3.2.7.tgz",
+      "integrity": "sha512-Trr0hYO9CM3Wj6ksWHRhK9IZpIY6wTMO5u/MqXurMxT57sWBaOPEtP3Oq60ihZuh5JsiagKfz95OcxdEP6dBrA==",
+      "dev": true,
+      "dependencies": {
+        "@vitest/spy": "3.2.7",
+        "estree-walker": "^3.0.3",
+        "magic-string": "^0.30.17"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "msw": "^2.4.9",
+        "vite": "^5.0.0 || ^6.0.0 || ^7.0.0-0"
+      },
+      "peerDependenciesMeta": {
+        "msw": {
+          "optional": true
+        },
+        "vite": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@vitest/mocker/node_modules/estree-walker": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-3.0.3.tgz",
+      "integrity": "sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==",
+      "dev": true,
+      "dependencies": {
+        "@types/estree": "^1.0.0"
+      }
+    },
+    "node_modules/@vitest/pretty-format": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-3.2.7.tgz",
+      "integrity": "sha512-KUHlwqVu0sRlhCdyPdQ/wBoTfRahjUky1MubOmYw9fWfIZy1gNoHpuaaQBPAaMaVYdQYHJLurzj8ECCj5OwTqA==",
+      "dev": true,
+      "dependencies": {
+        "tinyrainbow": "^2.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/runner": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/runner/-/runner-3.2.7.tgz",
+      "integrity": "sha512-sB9y4ovltoQP+WaUPwmSxO9WIg9Ig694Di5PalVPsYHklAdE027mehpWF2SQSVq+k6sFgaivbTjTJwZLSHbedA==",
+      "dev": true,
+      "dependencies": {
+        "@vitest/utils": "3.2.7",
+        "pathe": "^2.0.3",
+        "strip-literal": "^3.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/snapshot": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/snapshot/-/snapshot-3.2.7.tgz",
+      "integrity": "sha512-7C+MwShwtBSI5Buwoyg3s/iY1eHL9PKAf+O1wVh/TdnjXUtkoL/9YQtre90i4MtNXM6edP1wJ2zOBpfCyhIS7g==",
+      "dev": true,
+      "dependencies": {
+        "@vitest/pretty-format": "3.2.7",
+        "magic-string": "^0.30.17",
+        "pathe": "^2.0.3"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/spy": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/spy/-/spy-3.2.7.tgz",
+      "integrity": "sha512-Q2eQGI6d2L/hBtZ0qNuKcAGid68XK6cv1xsoaIma6PaJhHPoqcEJhYpXZ/5myCMqkNgtP6UKuBhbc0nHKnrkuQ==",
+      "dev": true,
+      "dependencies": {
+        "tinyspy": "^4.0.3"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/utils": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-3.2.7.tgz",
+      "integrity": "sha512-x6BDOd7dyo3PFLY3I9/HJ25X/6OurhGXk2/B9gOZNPF7XDVjeBK4k01lQE5uvDpbuheErh91qYuE1E2OEjK3Rw==",
+      "dev": true,
+      "dependencies": {
+        "@vitest/pretty-format": "3.2.7",
+        "loupe": "^3.1.4",
+        "tinyrainbow": "^2.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
     "node_modules/@volar/language-core": {
       "version": "2.4.15",
       "resolved": "https://registry.npmjs.org/@volar/language-core/-/language-core-2.4.15.tgz",
@@ -1162,6 +1257,15 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/assertion-error": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
+      "integrity": "sha512-Izi8RQcffqCeNVgFigKli1ssklIbpHnCYc6AknXGYoB6grJqyeby7jv12JUQgmTAnIDnbck1uxksT4dzN3PWBA==",
+      "dev": true,
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/autoprefixer": {
       "version": "10.5.4",
       "resolved": "https://registry.npmjs.org/autoprefixer/-/autoprefixer-10.5.4.tgz",
@@ -1289,6 +1393,15 @@
         "node": "^6 || ^7 || ^8 || ^9 || ^10 || ^11 || ^12 || >=13.7"
       }
     },
+    "node_modules/cac": {
+      "version": "6.7.14",
+      "resolved": "https://registry.npmjs.org/cac/-/cac-6.7.14.tgz",
+      "integrity": "sha512-b6Ilus+c3RrdDk+JhLKUAQfzzgLEPy6wcXqS7f/xe1EETvsDP6GORG7SFuOs6cID5YkqchW/LXZbX5bc8j7ZcQ==",
+      "dev": true,
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/camelcase-css": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/camelcase-css/-/camelcase-css-2.0.1.tgz",
@@ -1320,6 +1433,31 @@
       ],
       "license": "CC-BY-4.0"
     },
+    "node_modules/chai": {
+      "version": "5.3.3",
+      "resolved": "https://registry.npmjs.org/chai/-/chai-5.3.3.tgz",
+      "integrity": "sha512-4zNhdJD/iOjSH0A05ea+Ke6MU5mmpQcbQsSOkgdaUMJ9zTlDTD/GYlwohmIE2u0gaxHYiVHEn1Fw9mZ/ktJWgw==",
+      "dev": true,
+      "dependencies": {
+        "assertion-error": "^2.0.1",
+        "check-error": "^2.1.1",
+        "deep-eql": "^5.0.1",
+        "loupe": "^3.1.0",
+        "pathval": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "node_modules/check-error": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/check-error/-/check-error-2.1.3.tgz",
+      "integrity": "sha512-PAJdDJusoxnwm1VwW07VWwUN1sl7smmC3OKggvndJFadxxDRyFJBX/ggnu/KE4kQAB7a3Dp8f/YXC1FlUprWmA==",
+      "dev": true,
+      "engines": {
+        "node": ">= 16"
+      }
+    },
     "node_modules/chokidar": {
       "version": "3.6.0",
       "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-3.6.0.tgz",
@@ -1394,6 +1532,32 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/debug": {
+      "version": "4.4.3",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-4.4.3.tgz",
+      "integrity": "sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA==",
+      "dev": true,
+      "dependencies": {
+        "ms": "^2.1.3"
+      },
+      "engines": {
+        "node": ">=6.0"
+      },
+      "peerDependenciesMeta": {
+        "supports-color": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/deep-eql": {
+      "version": "5.0.2",
+      "resolved": "https://registry.npmjs.org/deep-eql/-/deep-eql-5.0.2.tgz",
+      "integrity": "sha512-h5k/5U50IJJFpzfL6nO9jaaumfjO/f2NjK/oYB2Djzm4p9L+3T9qWpZqZ2hAbLPuuYq9wrU08WQyBTL5GbPk5Q==",
+      "dev": true,
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/didyoumean": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/didyoumean/-/didyoumean-1.2.2.tgz",
@@ -1437,6 +1601,12 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/es-module-lexer": {
+      "version": "1.7.0",
+      "resolved": "https://registry.npmjs.org/es-module-lexer/-/es-module-lexer-1.7.0.tgz",
+      "integrity": "sha512-jEQoCwk8hyb2AZziIOLhDqpm5+2ww5uIE6lkO/6jcOCusfk6LhMHpXXfBLXTZ7Ydyt0j4VoUQv6uGNYbdW+kBA==",
+      "dev": true
+    },
     "node_modules/esbuild": {
       "version": "0.21.5",
       "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.21.5.tgz",
@@ -1492,6 +1662,15 @@
       "integrity": "sha512-Rfkk/Mp/DL7JVje3u18FxFujQlTNR2q6QfMSMB7AvCBx91NGj/ba3kCfza0f6dVDbw7YlRf/nDrn7pQrCCyQ/w==",
       "license": "MIT"
     },
+    "node_modules/expect-type": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/expect-type/-/expect-type-1.4.0.tgz",
+      "integrity": "sha512-KfYbmpRm0VbLjEvVa9yGwCi9GI34xvi7A/HXYWQO65CSD2u3MczUJSuwXKFIxlGsgBQizV9q5J9NHj4VG0n+pA==",
+      "dev": true,
+      "engines": {
+        "node": ">=12.0.0"
+      }
+    },
     "node_modules/fast-glob": {
       "version": "3.3.3",
       "resolved": "https://registry.npmjs.org/fast-glob/-/fast-glob-3.3.3.tgz",
@@ -1692,6 +1871,12 @@
         "jiti": "bin/jiti.js"
       }
     },
+    "node_modules/js-tokens": {
+      "version": "9.0.1",
+      "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-9.0.1.tgz",
+      "integrity": "sha512-mxa9E9ITFOt0ban3j6L5MpjwegGz6lBQmM1IJkWeBZGcMxto50+eWdjC/52xDbS2vy0k7vIMK0Fe2wfL9OQSpQ==",
+      "dev": true
+    },
     "node_modules/lilconfig": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/lilconfig/-/lilconfig-3.1.3.tgz",
@@ -1712,6 +1897,12 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/loupe": {
+      "version": "3.2.1",
+      "resolved": "https://registry.npmjs.org/loupe/-/loupe-3.2.1.tgz",
+      "integrity": "sha512-CdzqowRJCeLU72bHvWqwRBBlLcMEtIvGrlvef74kMnV2AolS9Y8xUv1I0U/MNAWMhBlKIoyuEgoJ0t/bbwHbLQ==",
+      "dev": true
+    },
     "node_modules/magic-string": {
       "version": "0.30.21",
       "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.30.21.tgz",
@@ -1761,6 +1952,12 @@
         "url": "https://github.com/sponsors/isaacs"
       }
     },
+    "node_modules/ms": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
+      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
+      "dev": true
+    },
     "node_modules/muggle-string": {
       "version": "0.4.1",
       "resolved": "https://registry.npmjs.org/muggle-string/-/muggle-string-0.4.1.tgz",
@@ -1852,6 +2049,21 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/pathe": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/pathe/-/pathe-2.0.3.tgz",
+      "integrity": "sha512-WUjGcAqP1gQacoQe+OBJsFA7Ld4DyXuUIjZ5cc75cLHvJ7dtNsTugphxIADwspS+AraAUePCKrSVtPLFj/F88w==",
+      "dev": true
+    },
+    "node_modules/pathval": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/pathval/-/pathval-2.0.1.tgz",
+      "integrity": "sha512-//nshmD55c46FuFw26xV/xFAaB5HF9Xdap7HJBBnrKdAd6/GxDBaNA1870O79+9ueg61cZLSVc+OaFlfmObYVQ==",
+      "dev": true,
+      "engines": {
+        "node": ">= 14.16"
+      }
+    },
     "node_modules/picocolors": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
@@ -2221,6 +2433,12 @@
         "queue-microtask": "^1.2.2"
       }
     },
+    "node_modules/siginfo": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/siginfo/-/siginfo-2.0.0.tgz",
+      "integrity": "sha512-ybx0WO1/8bSBLEWXZvEd7gMW3Sn3JFlW3TvX1nREbDLRNQNaeNN8WK0meBwPdAaOI7TtRRRJn/Es1zhrrCHu7g==",
+      "dev": true
+    },
     "node_modules/source-map-js": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/source-map-js/-/source-map-js-1.2.1.tgz",
@@ -2230,6 +2448,30 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/stackback": {
+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/stackback/-/stackback-0.0.2.tgz",
+      "integrity": "sha512-1XMJE5fQo1jGH6Y/7ebnwPOBEkIEnT4QF32d5R1+VXdXveM0IBMJt8zfaxX1P3QhVwrYe+576+jkANtSS2mBbw==",
+      "dev": true
+    },
+    "node_modules/std-env": {
+      "version": "3.10.0",
+      "resolved": "https://registry.npmjs.org/std-env/-/std-env-3.10.0.tgz",
+      "integrity": "sha512-5GS12FdOZNliM5mAOxFRg7Ir0pWz8MdpYm6AY6VPkGpbA7ZzmbzNcBJQ0GPvvyWgcY7QAhCgf9Uy89I03faLkg==",
+      "dev": true
+    },
+    "node_modules/strip-literal": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/strip-literal/-/strip-literal-3.1.0.tgz",
+      "integrity": "sha512-8r3mkIM/2+PpjHoOtiAW8Rg3jJLHaV7xPwG+YRGrv6FP0wwk/toTpATxWYOW0BKdWwl82VT2tFYi5DlROa0Mxg==",
+      "dev": true,
+      "dependencies": {
+        "js-tokens": "^9.0.1"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/antfu"
+      }
+    },
     "node_modules/sucrase": {
       "version": "3.35.1",
       "resolved": "https://registry.npmjs.org/sucrase/-/sucrase-3.35.1.tgz",
@@ -2327,6 +2569,18 @@
         "node": ">=0.8"
       }
     },
+    "node_modules/tinybench": {
+      "version": "2.9.0",
+      "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
+      "integrity": "sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==",
+      "dev": true
+    },
+    "node_modules/tinyexec": {
+      "version": "0.3.2",
+      "resolved": "https://registry.npmjs.org/tinyexec/-/tinyexec-0.3.2.tgz",
+      "integrity": "sha512-KQQR9yN7R5+OSwaK0XQoj22pwHoTlgYqmUscPYoknOoWCWfj/5/ABTMRi69FrKU5ffPVh5QcFikpWJI/P1ocHA==",
+      "dev": true
+    },
     "node_modules/tinyglobby": {
       "version": "0.2.17",
       "resolved": "https://registry.npmjs.org/tinyglobby/-/tinyglobby-0.2.17.tgz",
@@ -2375,6 +2629,33 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/tinypool": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/tinypool/-/tinypool-1.1.1.tgz",
+      "integrity": "sha512-Zba82s87IFq9A9XmjiX5uZA/ARWDrB03OHlq+Vw1fSdt0I+4/Kutwy8BP4Y/y/aORMo61FQ0vIb5j44vSo5Pkg==",
+      "dev": true,
+      "engines": {
+        "node": "^18.0.0 || >=20.0.0"
+      }
+    },
+    "node_modules/tinyrainbow": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-2.0.0.tgz",
+      "integrity": "sha512-op4nsTR47R6p0vMUUoYl/a+ljLFVtlfaXkLQmqfLR1qHma1h/ysYk4hEXZ880bf2CYgTskvTa/e196Vd5dDQXw==",
+      "dev": true,
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
+    "node_modules/tinyspy": {
+      "version": "4.0.6",
+      "resolved": "https://registry.npmjs.org/tinyspy/-/tinyspy-4.0.6.tgz",
+      "integrity": "sha512-u8KszXvGfU68hVcZpRHKG28T0krMuv2G5nDhiHaMLen/gIuFEgIJhaJuO69qjnXg5paSrbPMFfx3brNuN8eVSg==",
+      "dev": true,
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
     "node_modules/to-regex-range": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/to-regex-range/-/to-regex-range-5.0.1.tgz",
@@ -2507,6 +2788,112 @@
         }
       }
     },
+    "node_modules/vite-node": {
+      "version": "3.2.4",
+      "resolved": "https://registry.npmjs.org/vite-node/-/vite-node-3.2.4.tgz",
+      "integrity": "sha512-EbKSKh+bh1E1IFxeO0pg1n4dvoOTt0UDiXMd/qn++r98+jPO1xtJilvXldeuQ8giIB5IkpjCgMleHMNEsGH6pg==",
+      "dev": true,
+      "dependencies": {
+        "cac": "^6.7.14",
+        "debug": "^4.4.1",
+        "es-module-lexer": "^1.7.0",
+        "pathe": "^2.0.3",
+        "vite": "^5.0.0 || ^6.0.0 || ^7.0.0-0"
+      },
+      "bin": {
+        "vite-node": "vite-node.mjs"
+      },
+      "engines": {
+        "node": "^18.0.0 || ^20.0.0 || >=22.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/vitest": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/vitest/-/vitest-3.2.7.tgz",
+      "integrity": "sha512-KrxIJ62Fd89gfysR4WotlgZABiz2dqFPgqGzX7s+CwsqLFomRH7777ZcrOD6+WVAh7khPQP41A+BKbpcJFrdEg==",
+      "dev": true,
+      "dependencies": {
+        "@types/chai": "^5.2.2",
+        "@vitest/expect": "3.2.7",
+        "@vitest/mocker": "3.2.7",
+        "@vitest/pretty-format": "^3.2.7",
+        "@vitest/runner": "3.2.7",
+        "@vitest/snapshot": "3.2.7",
+        "@vitest/spy": "3.2.7",
+        "@vitest/utils": "3.2.7",
+        "chai": "^5.2.0",
+        "debug": "^4.4.1",
+        "expect-type": "^1.2.1",
+        "magic-string": "^0.30.17",
+        "pathe": "^2.0.3",
+        "picomatch": "^4.0.2",
+        "std-env": "^3.9.0",
+        "tinybench": "^2.9.0",
+        "tinyexec": "^0.3.2",
+        "tinyglobby": "^0.2.14",
+        "tinypool": "^1.1.1",
+        "tinyrainbow": "^2.0.0",
+        "vite": "^5.0.0 || ^6.0.0 || ^7.0.0-0",
+        "vite-node": "3.2.4",
+        "why-is-node-running": "^2.3.0"
+      },
+      "bin": {
+        "vitest": "vitest.mjs"
+      },
+      "engines": {
+        "node": "^18.0.0 || ^20.0.0 || >=22.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "@edge-runtime/vm": "*",
+        "@types/debug": "^4.1.12",
+        "@types/node": "^18.0.0 || ^20.0.0 || >=22.0.0",
+        "@vitest/browser": "3.2.7",
+        "@vitest/ui": "3.2.7",
+        "happy-dom": "*",
+        "jsdom": "*"
+      },
+      "peerDependenciesMeta": {
+        "@edge-runtime/vm": {
+          "optional": true
+        },
+        "@types/debug": {
+          "optional": true
+        },
+        "@types/node": {
+          "optional": true
+        },
+        "@vitest/browser": {
+          "optional": true
+        },
+        "@vitest/ui": {
+          "optional": true
+        },
+        "happy-dom": {
+          "optional": true
+        },
+        "jsdom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/vitest/node_modules/picomatch": {
+      "version": "4.0.7",
+      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.7.tgz",
+      "integrity": "sha512-qcJu88Q2IWqJsDD529JKMdwGm/dvInW4HvQnRwiH9JtihJvzGOscDtHE3x1pBKeUOTysQ8kVmLnJ2kJu7yhcGA==",
+      "dev": true,
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/jonschlinkert"
+      }
+    },
     "node_modules/vscode-uri": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/vscode-uri/-/vscode-uri-3.1.0.tgz",
@@ -2592,6 +2979,22 @@
       "peerDependencies": {
         "typescript": ">=5.0.0"
       }
+    },
+    "node_modules/why-is-node-running": {
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/why-is-node-running/-/why-is-node-running-2.3.0.tgz",
+      "integrity": "sha512-hUrmaWBdVDcxvYqnyh09zunKzROWjbZTiNy8dBEjkS7ehEDQibXJ7XvlmtbwuTclUiIyN+CyXQD4Vmko8fNm8w==",
+      "dev": true,
+      "dependencies": {
+        "siginfo": "^2.0.0",
+        "stackback": "0.0.2"
+      },
+      "bin": {
+        "why-is-node-running": "cli.js"
+      },
+      "engines": {
+        "node": ">=8"
+      }
     }
   }
 }

frontend/package.json

@@ -6,7 +6,8 @@
   "scripts": {
     "dev": "vite",
     "build": "vue-tsc --noEmit && vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run"
   },
   "dependencies": {
     "pinia": "^2.2.0",
@@ -20,6 +21,7 @@
     "tailwindcss": "^3.4.0",
     "typescript": "~5.5.0",
     "vite": "^5.4.0",
+    "vitest": "^3.2.7",
     "vue-tsc": "^2.1.0"
   }
 }

frontend/src/notes/colors.ts

@@ -169,9 +169,9 @@ export const NOTE_COLOR_LABELS: Record<NoteColor, string> = {
 // three implementations, and the same reason: a value that disagrees across surfaces
 // is a bug you cannot unsee and cannot explain.
 //
-// The Kotlin side has a unit test pinning the fixture below. THIS SIDE HAS NO
+// Both sides are pinned to the same values: `core/testdata/grammar.json` (`tint`),
-// MECHANICAL GUARD — the frontend has no test runner, only `vue-tsc --noEmit`.
+// which `notes/grammar.test.ts` reads, and DerivedTintTest.kt, which writes the same
-// If you change anything here, check it against the fixture by hand.
+// numbers out by hand. Change the hash or the key order and both go red.
 export const DERIVED_TINT_KEYS: readonly NoteColor[] = NOTE_COLOR_KEYS.filter(
   (key) => key !== "default",
 );
@@ -235,22 +235,8 @@ export function resolveLabelColor(label: { name: string; color?: string | null }
   return derivedTint(label.name.toLowerCase());
 }
 
-// Fixture — the same names and expected keys the Kotlin test asserts. Kept here as
+// The fixture (four UUID hashes and seven tag names) lives in
-// prose because there is nowhere on this side to assert it. If you change the hash or
+// core/testdata/grammar.json under `tint`.
-// the key order, these must still hold on BOTH surfaces.
-//
-// The raw hash, over four UUIDs — ids no longer pick a colour, but they are what the
-// hash itself is pinned by and the Kotlin test still asserts them:
-//
-//   00000000-0000-0000-0000-000000000000  0xbe478ed1  purple
-//   11111111-1111-1111-1111-111111111111  0x3d75cc01  blue
-//   6ba7b810-9dad-11d1-80b4-00c04fd430c8  0xf108e530  orange
-//   f47ac10b-58cc-4372-a567-0e02b2c3d479  0x5b651540  orange
-//
-// And the live path — a label, hashing its lowercased NAME:
-//
-//   todo -> pink     grocery -> blue    work -> green    home -> gray
-//   ideas -> green   reading -> gray    urgent -> red
 //
 // Note `work`/`ideas` and `home`/`reading` collide. Nine keys makes that unavoidable
 // and it is not a bug: colour hints that two tags are distinct, it never claims two

frontend/src/notes/grammar.test.ts

@@ -0,0 +1,54 @@
+// The web's half of the shared grammar fixture (core/testdata/grammar.json).
+//
+// The same cases run against the core (derive.rs) and the server (checklist.py,
+// tags.py). Until this file the web copy had no mechanical guard at all — the
+// frontend's only CI lane was `vue-tsc --noEmit` — so a drift here showed up as a
+// checklist or a tag colour that differed in the browser and nowhere else.
+import { describe, expect, it } from "vitest";
+import fixture from "../../../core/testdata/grammar.json";
+import { DERIVED_TINT_KEYS, derivedTint, resolveLabelColor, tintHash } from "./colors";
+import { parseInline, parseTaskLine, renderTaskLine } from "./markdown";
+
+describe("checklist lines", () => {
+  it.each(fixture.task_lines)("$line", ({ line, item }) => {
+    expect(parseTaskLine(line)).toEqual(item);
+  });
+
+  it.each(fixture.rendered_items)("renders $line", ({ text, checked, line }) => {
+    expect(renderTaskLine(text, checked)).toBe(line);
+  });
+});
+
+describe("tags", () => {
+  // The renderer finds tags; it does not collect them. Collected here line by line
+  // and deduped the way the derivers dedupe — first spelling wins, case-insensitively.
+  function tagsOf(body: string): string[] {
+    const out: string[] = [];
+    for (const line of body.split("\n")) {
+      for (const token of parseInline(line)) {
+        if (token.type !== "tag") continue;
+        if (!out.some((t) => t.toLowerCase() === token.value.toLowerCase())) out.push(token.value);
+      }
+    }
+    return out;
+  }
+
+  it.each(fixture.tags)("$body", ({ body, tags }) => {
+    expect(tagsOf(body)).toEqual(tags);
+  });
+});
+
+describe("derived tag colour", () => {
+  it("uses the same key order as Android", () => {
+    expect([...DERIVED_TINT_KEYS]).toEqual(fixture.tint.keys);
+  });
+
+  it.each(fixture.tint.hashes)("hashes $id", ({ id, hash, color }) => {
+    expect(tintHash(id)).toBe(hash);
+    expect(derivedTint(id)).toBe(color);
+  });
+
+  it.each(fixture.tint.names)("colours #$name", ({ name, color }) => {
+    expect(resolveLabelColor({ name })).toBe(color);
+  });
+});

frontend/src/stores/titles.test.ts

@@ -0,0 +1,40 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { createPinia, setActivePinia } from "pinia";
+
+vi.mock("../adapters", () => ({ repo: { notes: { titles: vi.fn() } } }));
+
+import { repo } from "../adapters";
+import { useTitlesStore } from "./titles";
+
+describe("the palette's note titles", () => {
+  beforeEach(() => setActivePinia(createPinia()));
+
+  // #5165: the list loaded once per session, so a note written after the palette
+  // first opened could not be found by name until the page reloaded.
+  it("sees a note written since the last open", async () => {
+    vi.mocked(repo.notes.titles)
+      .mockResolvedValueOnce([{ id: "a", title: "Groceries" }])
+      .mockResolvedValueOnce([
+        { id: "a", title: "Groceries" },
+        { id: "b", title: "Trip" },
+      ]);
+    const titles = useTitlesStore();
+
+    await titles.refresh();
+    expect(titles.items.map((t) => t.title)).toEqual(["Groceries"]);
+
+    await titles.refresh();
+    expect(titles.items.map((t) => t.title)).toEqual(["Groceries", "Trip"]);
+  });
+
+  it("keeps the last list when a refresh fails", async () => {
+    vi.mocked(repo.notes.titles)
+      .mockResolvedValueOnce([{ id: "a", title: "Groceries" }])
+      .mockRejectedValueOnce(new Error("offline"));
+    const titles = useTitlesStore();
+
+    await titles.refresh();
+    await expect(titles.refresh()).rejects.toThrow("offline");
+    expect(titles.items.map((t) => t.title)).toEqual(["Groceries"]);
+  });
+});

tests/test_grammar_fixture.py

@@ -0,0 +1,43 @@
+"""The server's half of the shared grammar fixture (core/testdata/grammar.json).
+
+The same cases run against the core (derive.rs) and the web (markdown.ts). A case
+that passes in one language and fails in another is a note that changes shape when
+it syncs — a checklist that stops being one, or a tag that is a label on the phone
+and plain text on the server.
+"""
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+
+from inkwell.notes.checklist import parse_items, render_item
+from inkwell.notes.tags import parse_tags, split_body_tags
+
+FIXTURE = json.loads(
+    (Path(__file__).resolve().parents[1] / "core" / "testdata" / "grammar.json").read_text(encoding="utf-8")
+)
+
+
+@pytest.mark.parametrize("case", FIXTURE["task_lines"], ids=lambda c: repr(c["line"]))
+def test_task_lines(case):
+    got = [(i.text, i.checked) for i in parse_items(case["line"])]
+    want = [] if case["item"] is None else [(case["item"]["text"], case["item"]["checked"])]
+    assert got == want
+
+
+@pytest.mark.parametrize("case", FIXTURE["rendered_items"], ids=lambda c: repr(c["line"]))
+def test_rendered_items(case):
+    assert render_item(case["text"], case["checked"]) == case["line"]
+
+
+@pytest.mark.parametrize("case", FIXTURE["tags"], ids=lambda c: repr(c["body"]))
+def test_tags(case):
+    assert parse_tags(case["body"]) == case["tags"]
+
+
+@pytest.mark.parametrize("case", FIXTURE["lifts"], ids=lambda c: repr(c["body"]))
+def test_lifts(case):
+    standalone, inline, lifted = split_body_tags(case["body"])
+    assert (standalone, inline, lifted) == (case["standalone"], case["inline"], case["lifted"])