Add snapshot tests to catch regressions not covered in tests

This commit has been cherry picked from its original appearance in #164, with the following changes:

- Include all enketo-core fixtures in preparation for adding benchmarks to establish a performance baseline.
- Temporarily increase the timeout for snapshot tests so that the longer running enketo-core fixtures can generate initial snapshots.
- Restore test shuffling (turning that off was a mistake in the original TypeScript PR).
- Switch the default test reporter to `dot` to improve visibility of progress during test runs (it's still not great, mainly due to performance).
- Move `linkedom` stuff to `/test/shared.ts` as it will only be used in tests.
- Accept updates to `package-lock.json` with SHA-512 integrity hashes.
- Excludes formatting of XML/XSL.

About snapshot serialization:

Snapshots use a custom serializer designed to identify only meaningful differences. This means that a snapshot matches if:

- the value is exactly equal
- the value is equal, apart from insignificant changes to whitespace and/or attribute order

The serialization logic:

1. Manually ensures consistent attribute order (using `linkedom` as a DOM compatibility library, primarily because its types are much better than those for `@xmldom/xmldom`).
2. Uses `prettier` to normalize whitespace.
3. Uses `pretty-format` (`vitest`'s default) for final serialization.

Apart from adding snapshots, tests have been updated to reference `linkedom`'s types (corrected where necessary) and to its behavior (which is semantically equivalent to the previous `@xmldom/xmldom` usage, but more consistent with a real DOM environment).

.eslintignore

@@ -0,0 +1,2 @@
+**/*.xml
+**/*.xsl

.eslintrc.json

@@ -101,6 +101,10 @@
                 "@typescript-eslint/no-unused-vars": "error",
                 "no-empty-function": "off",
                 "@typescript-eslint/no-empty-function": "error",
+                "no-undef": "off",
+                "no-redeclare": "off",
+                "@typescript-eslint/no-redeclare": "error",
+                "import/no-unresolved": "off",
 
                 "import/extensions": [
                     "error",

.prettierignore

@@ -5,3 +5,5 @@
 dist/*
 docs/*
 test-coverage/*
+src/xsl/**
+test/**/*.xml

.vscode/settings.json

@@ -23,6 +23,14 @@
         "editor.formatOnSave": true
     },
 
+    // Note: it would be nice to reverse this! But it's currently preventing a *ton* of whitespace diff noise
+    "[xml]": {
+        "editor.formatOnSave": false
+    },
+    "[xsl]": {
+        "editor.formatOnSave": false
+    },
+
     // Code navigation
     "javascript.referencesCodeLens.enabled": true
 }

package.json

@@ -53,19 +53,25 @@
     ],
     "dependencies": {
         "body-parser": "^1.20.1",
+        "css.escape": "^1.5.1",
         "express": "^4.18.2",
         "language-tags": "1.0.5",
         "libxslt": "0.10.0",
+        "linkedom": "^0.14.21",
+        "prettier": "^2.8.1",
         "string-direction": "0.1.x",
-        "undici": "^5.13.0"
+        "undici": "^5.13.0",
+        "xpath-to-css": "^1.1.0"
     },
     "devDependencies": {
+        "@prettier/plugin-xml": "^2.2.0",
+        "@types/css.escape": "^1.5.0",
         "@types/express": "^4.17.14",
         "@types/node": "^18.11.17",
+        "@types/prettier": "^2.7.2",
         "@typescript-eslint/eslint-plugin": "^5.47.0",
         "@typescript-eslint/parser": "^5.47.0",
         "@vitest/coverage-istanbul": "^0.26.2",
-        "@xmldom/xmldom": "^0.7.9",
         "chai": "^4.3.7",
         "chai-as-promised": "^7.1.1",
         "docdash": "^1.2.0",
@@ -85,7 +91,8 @@
         "http-server": "^13.1.0",
         "istanbul-reporter-shield-badge": "^1.2.1",
         "markdown-eslint-parser": "^1.2.1",
-        "prettier": "^2.8.1",
+        "pretty-format": "^29.3.1",
+        "rimraf": "^3.0.2",
         "typescript": "^4.9.4",
         "vite": "^4.0.3",
         "vite-plugin-node": "^1.0.0",