feat: export toValueSync & defaultOptions to evaluate expression, see #527

Author: harttle

src/parser/tokenizer.ts

@@ -33,7 +33,7 @@ export class Tokenizer {
 
   constructor (
     public input: string,
-    private trie: Trie,
+    private trie: Trie = defaultOptions.operatorsTrie,
     public file: string = ''
   ) {
     this.N = input.length

src/render/expression.ts

@@ -20,7 +20,7 @@ export class Expression {
   public constructor (tokens: IterableIterator<Token>) {
     this.postfix = [...toPostfix(tokens)]
   }
-  public * evaluate (ctx: Context, lenient: boolean): Generator<unknown, unknown, unknown> {
+  public * evaluate (ctx: Context, lenient?: boolean): Generator<unknown, unknown, unknown> {
     assert(ctx, 'unable to evaluate: context not defined')
     const operands: any[] = []
     for (const token of this.postfix) {

src/types.ts

@@ -21,10 +21,11 @@ export { Tokenizer } from './parser/tokenizer'
 export { Hash } from './template/tag/hash'
 export { Value } from './template/value'
 export { evalToken, evalQuotedToken } from './render/expression'
-export { toPromise, toThenable } from './util/async'
+export { toPromise, toThenable, toValueSync } from './util/async'
 export { defaultOperators, Operators } from './render/operator'
 export { createTrie, Trie } from './util/operator-trie'
 export { toValue } from './util/underscore'
 export { TimezoneDate } from './util/timezone-date'
 export * as filters from './builtin/filters'
 export * as tags from './builtin/tags'
+export { defaultOptions } from './liquid-options'

test/e2e/issues.ts

@@ -1,4 +1,4 @@
-import { Liquid, Drop } from '../..'
+import { Tokenizer, Context, Liquid, Drop, defaultOptions, toValueSync } from '../..'
 import { expect, use } from 'chai'
 import * as chaiAsPromised from 'chai-as-promised'
 import * as sinon from 'sinon'
@@ -260,4 +260,10 @@ describe('Issues', function () {
     const engine = new Liquid()
     expect(() => engine.parse('{% assign headshot = https://testurl.com/not_enclosed_in_quotes.jpg %}')).to.throw(/unexpected token at ":/)
   })
+  it('#527 export Liquid Expression', () => {
+    const tokenizer = new Tokenizer('a > b', defaultOptions.operatorsTrie)
+    const expression = tokenizer.readExpression()
+    const result = toValueSync(expression.evaluate(new Context({ a: 1, b: 2 })))
+    expect(result).to.equal(false)
+  })
 })

test/integration/liquid/liquid.ts

@@ -199,7 +199,7 @@ describe('Liquid', function () {
   describe('#enderToNodeStream', function () {
     const engine = new Liquid()
     it('should render a simple value', async () => {
-      const stream = await engine.renderToNodeStream(engine.parse('{{"foo"}}'))
+      const stream = engine.renderToNodeStream(engine.parse('{{"foo"}}'))
       expect(drainStream(stream)).to.eventually.equal('foo')
     })
   })

test/unit/parser/tokenizer.ts

@@ -17,7 +17,7 @@ describe('Tokenizer', function () {
   const trie = createTrie(defaultOperators)
 
   it('should read quoted', () => {
-    expect(new Tokenizer('"foo" ff', trie).readQuoted()!.getText()).to.equal('"foo"')
+    expect(new Tokenizer('"foo" ff').readQuoted()!.getText()).to.equal('"foo"')
     expect(new Tokenizer(' "foo"ff', trie).readQuoted()!.getText()).to.equal('"foo"')
   })
   it('should read value', () => {