add component state, top-level await support (#26)

1 files changed, 83 insertions, 0 deletions

diff --git a/src/compiler/optimize/index.ts b/src/compiler/optimize/index.ts
new file mode 100644
index 000000000..4f6e54fa5
--- /dev/null
+++ b/src/compiler/optimize/index.ts
@@ -0,0 +1,83 @@
+import { walk } from 'estree-walker';
+import type { Ast, TemplateNode } from '../../parser/interfaces';
+import { NodeVisitor, Optimizer, VisitorFn } from '../../@types/optimizer';
+import optimizeStyles from './styles.js';
+
+interface VisitorCollection {
+  enter: Map<string, VisitorFn[]>;
+  leave: Map<string, VisitorFn[]>;
+}
+
+function addVisitor(visitor: NodeVisitor, collection: VisitorCollection, nodeName: string, event: 'enter' | 'leave') {
+  if (typeof visitor[event] !== 'function') return;
+  if (!collection[event]) collection[event] = new Map<string, VisitorFn[]>();
+
+  const visitors = collection[event].get(nodeName) || [];
+  visitors.push(visitor[event] as any);
+  collection[event].set(nodeName, visitors);
+}
+
+function collectVisitors(optimizer: Optimizer, htmlVisitors: VisitorCollection, cssVisitors: VisitorCollection, finalizers: Array<() => Promise<void>>) {
+  if (optimizer.visitors) {
+    if (optimizer.visitors.html) {
+      for (const [nodeName, visitor] of Object.entries(optimizer.visitors.html)) {
+        addVisitor(visitor, htmlVisitors, nodeName, 'enter');
+        addVisitor(visitor, htmlVisitors, nodeName, 'leave');
+      }
+    }
+    if (optimizer.visitors.css) {
+      for (const [nodeName, visitor] of Object.entries(optimizer.visitors.css)) {
+        addVisitor(visitor, cssVisitors, nodeName, 'enter');
+        addVisitor(visitor, cssVisitors, nodeName, 'leave');
+      }
+    }
+  }
+  finalizers.push(optimizer.finalize);
+}
+
+function createVisitorCollection() {
+  return {
+    enter: new Map<string, VisitorFn[]>(),
+    leave: new Map<string, VisitorFn[]>(),
+  };
+}
+
+function walkAstWithVisitors(tmpl: TemplateNode, collection: VisitorCollection) {
+  walk(tmpl, {
+    enter(node) {
+      if (collection.enter.has(node.type)) {
+        const fns = collection.enter.get(node.type)!;
+        for (let fn of fns) {
+          fn(node);
+        }
+      }
+    },
+    leave(node) {
+      if (collection.leave.has(node.type)) {
+        const fns = collection.leave.get(node.type)!;
+        for (let fn of fns) {
+          fn(node);
+        }
+      }
+    },
+  });
+}
+
+interface OptimizeOptions {
+  filename: string;
+  fileID: string;
+}
+
+export async function optimize(ast: Ast, opts: OptimizeOptions) {
+  const htmlVisitors = createVisitorCollection();
+  const cssVisitors = createVisitorCollection();
+  const finalizers: Array<() => Promise<void>> = [];
+
+  collectVisitors(optimizeStyles(opts), htmlVisitors, cssVisitors, finalizers);
+
+  walkAstWithVisitors(ast.css, cssVisitors);
+  walkAstWithVisitors(ast.html, htmlVisitors);
+
+  // Run all of the finalizer functions in parallel because why not.
+  await Promise.all(finalizers.map((fn) => fn()));
+}