0.9.2: Source view, schema checks without the YAML extension

Every Archify page can show its file's YAML in place. Diagrams get
Diagram | Graph | Source (Graph only inside a model), main.archify
Model | Graph | Source, registry and decision pages View | Source, and the
Graph page a Source segment. 2D | 3D moves left of that switch and hides
while Source shows.

The YAML opens in a CodeMirror editor inside the page (dist/source.js,
loaded on first use), themed with the page's colours. Edits go to the VS
Code document as WorkspaceEdits; outside changes come back to the page.
Undo and redo are the editor's own, since VS Code sends ⌘Z in a focused
webview to the webview; save and find stay VS Code's. Problems come from
the host only (what the Problems panel holds for the file) and are
counted on the Source segment; completion and hover come from the schema,
folded into one draft-07 document per diagram type.

The host now checks .archify files against the extension's schema with
ajv on the YAML as written, before archify validate, and checks
.archify-registry files against the registry schema for the first time.
Registry and decision pages become text editor providers. While Source
shows, new renders wait and appear when the picture comes back.

Show Source switches the page to Source; Open in Text Editor (the editor
title button) opens the text beside it, as Show Source did. The decision
schema is no longer given to the YAML extension. Fixed: YAML errors in
registry and decision files were reported on line 1; "Webview is
disposed" when a diagram closed mid-render; the model heading under the
toolbar in narrow editors.

src/language/editorSchemas.ts

@@ -0,0 +1,85 @@
+import { DIAGRAM_SCHEMA, REGISTRY_SCHEMA } from './schemaCheck';
+
+type Json = null | boolean | number | string | Json[] | { [key: string]: Json };
+
+/**
+ * Schemas for completion and hover in the Source view. The editor's schema
+ * library reads one draft-07 document, while ours are 2020-12 files that
+ * refer to each other; so the referenced files are folded into `$defs` and
+ * 2020-12 tuples become draft-07 ones. Problems never come from these
+ * copies (the host checks with the originals), only suggestions.
+ */
+export class EditorSchemas {
+  private readonly cache = new Map<string, object>();
+
+  constructor(private readonly schemas: Record<string, object>) {}
+
+  /** The schema for a file kind; for diagrams the one of its diagram_type. */
+  forSource(kind: 'diagram' | 'registry' | 'decision', text: string): { key: string; schema: object } | undefined {
+    if (kind === 'decision') return undefined;
+    if (kind === 'registry') return this.get(REGISTRY_SCHEMA);
+    const type = /^diagram_type:\s*["']?([a-z]+)/m.exec(text)?.[1];
+    const name = type && this.schemas[`${type}.schema.json`] ? `${type}.schema.json` : DIAGRAM_SCHEMA;
+    return this.get(name);
+  }
+
+  private get(name: string): { key: string; schema: object } | undefined {
+    if (!this.schemas[name]) return undefined;
+    if (!this.cache.has(name)) this.cache.set(name, bundleSchema(this.schemas, name));
+    return { key: name, schema: this.cache.get(name)! };
+  }
+}
+
+const defKey = (file: string) => `file:${file}`;
+
+/** One self-contained draft-07 shaped schema for `root` and every file it refers to. */
+export function bundleSchema(schemas: Record<string, object>, root: string): object {
+  const files = new Set<string>([root]);
+  const queue = [root];
+  while (queue.length) {
+    const file = queue.shift()!;
+    for (const ref of refsOf(schemas[file] as Json)) {
+      const target = ref.split('#')[0];
+      if (target && !files.has(target) && schemas[target]) {
+        files.add(target);
+        queue.push(target);
+      }
+    }
+  }
+  const base = (file: string) => (file === root ? '#' : `#/$defs/${defKey(file)}`);
+  const rewrite = (node: Json, file: string): Json => {
+    if (Array.isArray(node)) return node.map((item) => rewrite(item, file));
+    if (!node || typeof node !== 'object') return node;
+    const out: { [key: string]: Json } = {};
+    for (const [key, value] of Object.entries(node)) {
+      if (key === '$ref' && typeof value === 'string') {
+        const [target, pointer = ''] = value.split('#');
+        out.$ref = `${base(target || file)}${pointer}`;
+      } else if (key !== '$schema' && key !== '$id') {
+        out[key] = rewrite(value, file);
+      }
+    }
+    if (out.prefixItems) {
+      if (out.items === false) out.additionalItems = false;
+      else if (out.items !== undefined) out.additionalItems = out.items;
+      out.items = out.prefixItems;
+      delete out.prefixItems;
+    }
+    return out;
+  };
+  const bundled = rewrite(schemas[root] as Json, root) as { [key: string]: Json };
+  const defs = { ...((bundled.$defs as { [key: string]: Json } | undefined) ?? {}) };
+  for (const file of files) if (file !== root) defs[defKey(file)] = rewrite(schemas[file] as Json, file);
+  return { ...bundled, $defs: defs };
+}
+
+function refsOf(node: Json, out: string[] = []): string[] {
+  if (Array.isArray(node)) node.forEach((item) => refsOf(item, out));
+  else if (node && typeof node === 'object') {
+    for (const [key, value] of Object.entries(node)) {
+      if (key === '$ref' && typeof value === 'string') out.push(value);
+      else refsOf(value, out);
+    }
+  }
+  return out;
+}