docs: brand logo in the README; test that the dialects table matches each dialect's capabilities

README.md

@@ -1,4 +1,9 @@
-# restloom
+<h1 align="center">
+  <picture>
+    <source media="(prefers-color-scheme: dark)" srcset=".github/brand/logo-dark.svg">
+    <img alt="restloom" src=".github/brand/logo-light.svg" height="110">
+  </picture>
+</h1>
 
 A REST API generated from your database's catalog. Name the schemas or tables to serve, and restloom reads their columns, types, keys and relations, and answers queries like this one:
 

conformance/dialects-doc.test.mjs

@@ -0,0 +1,36 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import { postgres } from '../packages/postgres/dist/index.js';
+import { mysql } from '../packages/mysql/dist/index.js';
+import { mssql } from '../packages/mssql/dist/index.js';
+import { sqlite } from '../packages/sqlite/dist/index.js';
+
+// The table in docs/dialects.md is what readers compare databases by, on the
+// site too. It must say what each dialect's capabilities say.
+const DIALECTS = {
+    '@crudy/restloom-postgres': postgres({}),
+    '@crudy/restloom-mysql': mysql({}),
+    '@crudy/restloom-mssql': mssql({}),
+    '@crudy/restloom-sqlite': sqlite({ pragma() {} }),
+};
+
+const rows = readFileSync(new URL('../docs/dialects.md', import.meta.url), 'utf8')
+    .split('\n')
+    .filter((line) => line.startsWith('| `@crudy/restloom-'))
+    .map((line) => line.split('|').slice(1, -1).map((cell) => cell.trim()));
+
+test('docs/dialects.md lists every dialect', () => {
+    assert.deepEqual(rows.map((r) => r[0].replaceAll('`', '')).sort(), Object.keys(DIALECTS).sort());
+});
+
+for (const [pkg, dialect] of Object.entries(DIALECTS)) {
+    test(`docs/dialects.md says what ${pkg} can do`, () => {
+        const [, , , written, estimated, rowSecurity, procedures] = rows.find((r) => r[0] === `\`${pkg}\``);
+        const c = dialect.capabilities;
+        assert.equal(/RETURNING|OUTPUT/.test(written), c.returning, 'written keys');
+        assert.equal(estimated !== 'no', c.estimatedCount, 'estimated count');
+        assert.equal(rowSecurity !== 'no', c.rowSecurity, 'row security');
+        assert.equal(procedures !== 'none', c.procedures, 'procedures');
+    });
+}