Merge pull request #49 from getlang-dev/macros-and-modifiers

macros and modifiers

Author: mattfysh

bun.lock

@@ -2,7 +2,7 @@
   "name": "get",
   "license": "Apache-2.0",
   "private": true,
-  "packageManager": "bun@1.2.20",
+  "packageManager": "bun@1.2.21",
   "scripts": {
     "fmt": "biome check --write",
     "lint": "bun lint:check && bun lint:types && bun lint:unused && bun lint:repo",
@@ -18,11 +18,11 @@
     "test"
   ],
   "devDependencies": {
-    "@biomejs/biome": "^2.2.0",
+    "@biomejs/biome": "^2.2.3",
     "@changesets/changelog-github": "^0.5.1",
     "@changesets/cli": "^2.29.6",
-    "@types/bun": "^1.2.20",
-    "knip": "^5.62.0",
+    "@types/bun": "^1.2.21",
+    "knip": "^5.63.1",
     "sherif": "^1.6.1",
     "typescript": "^5.9.2"
   }

bun.lockb

@@ -20,8 +20,9 @@
     "@getlang/ast": "workspace:^0.0.1",
     "@getlang/lib": "workspace:^0.1.5",
     "@getlang/parser": "workspace:^0.3.4",
-    "@getlang/utils": "workspace:^0.1.6",
     "@getlang/walker": "workspace:^0.0.1",
+    "acorn": "^8.15.0",
+    "estree-toolkit": "^1.7.13",
     "lodash-es": "^4.17.21"
   },
   "devDependencies": {

package.json

@@ -0,0 +1,98 @@
+import type { TypeInfo } from '@getlang/ast'
+import { Type } from '@getlang/ast'
+import type { Hooks, Inputs } from '@getlang/lib'
+import { cookies, html, invariant, js, json } from '@getlang/lib'
+import { ImportError, ValueReferenceError } from '@getlang/lib/errors'
+import { partition } from 'lodash-es'
+import type { Entry, Registry } from './registry.js'
+import type { RuntimeValue } from './value.js'
+import { materialize } from './value.js'
+
+export async function callModifier(
+  registry: Registry,
+  mod: string,
+  args: Record<string, unknown>,
+  context?: RuntimeValue,
+) {
+  const entry = await registry.importMod(mod)
+  if (entry) {
+    return entry.mod(context?.data, args)
+  }
+
+  invariant(context, 'Modifier requires context')
+
+  if (mod === 'link') {
+    invariant(typeof args.base === 'string', '@link requires base url')
+    const data = html.findLink(context.data)
+    const link = materialize({ data, typeInfo: context.typeInfo })
+    return new URL(link, args.base).toString()
+  }
+
+  const doc = materialize(context)
+
+  switch (mod) {
+    case 'html':
+      return html.parse(doc)
+    case 'js':
+      return js.parse(doc)
+    case 'json':
+      return json.parse(doc)
+    case 'cookies':
+      return cookies.parse(doc)
+    default:
+      throw new ValueReferenceError(`Unsupported modifier: ${mod}`)
+  }
+}
+
+export type Execute = (entry: Entry, inputs: Inputs) => Promise<any>
+
+export async function callModule(
+  registry: Registry,
+  execute: Execute,
+  hooks: Required<Hooks>,
+  module: string,
+  args: RuntimeValue,
+  contextType?: TypeInfo,
+) {
+  let entry: Entry
+  try {
+    entry = await registry.import(module, [], contextType)
+  } catch (e) {
+    const err = `Failed to import module: ${module}`
+    throw new ImportError(err, { cause: e })
+  }
+  const [inputArgs, attrArgs] = partition(Object.entries(args.data), e =>
+    entry.inputs.has(e[0]),
+  )
+  const inputs = Object.fromEntries(inputArgs)
+  let extracted = await hooks.call(module, inputs)
+  if (typeof extracted === 'undefined') {
+    extracted = await execute(entry, inputs)
+  }
+  await hooks.extract(module, inputs, extracted.data)
+
+  function dropWarning(reason: string) {
+    if (attrArgs.length) {
+      const dropped = attrArgs.map(e => e[0]).join(', ')
+      const err = [
+        `Module '${module}' ${reason}`,
+        `dropping view attributes: ${dropped}`,
+      ].join(', ')
+      console.warn(err)
+    }
+  }
+
+  if (entry.returnType.type !== Type.Value) {
+    dropWarning('returned unmaterialized value')
+    return extracted
+  }
+
+  if (typeof extracted !== 'object') {
+    dropWarning('returned a primitive')
+    return extracted
+  }
+
+  const data = Object.fromEntries(attrArgs)
+  const raster = materialize({ data, typeInfo: args.typeInfo })
+  return { ...raster, ...extracted }
+}