refactor: Tag class support in registerTag()

src/template/value.ts

@@ -1,8 +1,9 @@
-import { Expression } from '../render/expression'
-import { Tokenizer } from '../parser/tokenizer'
-import { Filter } from './filter/filter'
-import { Context } from '../context/context'
-import { Liquid } from '../liquid'
+import { Filter } from './filter'
+import { Expression } from '../render'
+import { Tokenizer } from '../parser'
+import { assert } from '../util'
+import type { Liquid } from '../liquid'
+import type { Context } from '../context'
 
 export class Value {
   public readonly filters: Filter[] = []
@@ -14,7 +15,7 @@ export class Value {
   public constructor (str: string, liquid: Liquid) {
     const tokenizer = new Tokenizer(str, liquid.options.operators)
     this.initial = tokenizer.readExpression()
-    this.filters = tokenizer.readFilters().map(({ name, args }) => new Filter(name, liquid.filters.get(name), args, liquid))
+    this.filters = tokenizer.readFilters().map(({ name, args }) => new Filter(name, this.getFilter(liquid, name), args, liquid))
   }
   public * value (ctx: Context, lenient: boolean): Generator<unknown, unknown, unknown> {
     lenient = lenient || (ctx.opts.lenientIf && this.filters.length > 0 && this.filters[0].name === 'default')
@@ -25,4 +26,9 @@ export class Value {
     }
     return val
   }
+  private getFilter (liquid: Liquid, name: string) {
+    const impl = liquid.filters[name]
+    assert(impl || !liquid.options.strictFilters, () => `undefined filter: ${name}`)
+    return impl
+  }
 }