feat: use evalValue to parse & render expression, #527

Author: harttle

src/liquid.ts

@@ -90,15 +90,16 @@ export class Liquid {
     return this.renderToNodeStream(templates, scope, renderOptions)
   }
 
-  public _evalValue (str: string, ctx: Context): IterableIterator<any> {
+  public _evalValue (str: string, scopeOrContext?: object | Context): IterableIterator<any> {
     const value = new Value(str, this)
+    const ctx = scopeOrContext instanceof Context ? scopeOrContext : new Context(scopeOrContext, this.options)
     return value.value(ctx, false)
   }
-  public async evalValue (str: string, ctx: Context): Promise<any> {
-    return toPromise(this._evalValue(str, ctx))
+  public async evalValue (str: string, scopeOrContext?: object | Context): Promise<any> {
+    return toPromise(this._evalValue(str, scopeOrContext))
   }
-  public evalValueSync (str: string, ctx: Context): any {
-    return toValueSync(this._evalValue(str, ctx))
+  public evalValueSync (str: string, scopeOrContext?: object | Context): any {
+    return toValueSync(this._evalValue(str, scopeOrContext))
   }
 
   public registerFilter (name: string, filter: FilterImplOptions) {

test/e2e/eval-value.ts

@@ -1,12 +1,32 @@
 import { expect } from 'chai'
-import { Liquid } from '../..'
+import { Context, Liquid } from '../..'
 
 describe('#evalValue()', function () {
   var engine: Liquid
-  beforeEach(() => { engine = new Liquid() })
+  beforeEach(() => { engine = new Liquid({ globals: { foo: 'FOO' } }) })
 
-  it('should eval value', async function () {
-    const val = await engine.evalValue('true', { opts: {} } as any)
+  it('should support boolean', async function () {
+    const val = await engine.evalValue('true')
     expect(val).to.equal(true)
   })
+
+  it('should support binary expression with Context', async function () {
+    const val = await engine.evalValue('a > b', { a: 1, b: 2 })
+    expect(val).to.equal(false)
+  })
+
+  it('should inherit Liquid options', async function () {
+    const val = await engine.evalValue('foo')
+    expect(val).to.equal('FOO')
+  })
+
+  it('should support passing Context', async function () {
+    const val = await engine.evalValue('a > b', new Context({ a: 1, b: 2 }))
+    expect(val).to.equal(false)
+  })
+
+  it('should respect options in passed in Context', async function () {
+    const val = await engine.evalValue('foo', new Context({}, { globals: { foo: 'BAR' } } as any))
+    expect(val).to.equal('BAR')
+  })
 })

test/e2e/issues.ts

@@ -266,4 +266,14 @@ describe('Issues', function () {
     const result = toValueSync(expression.evaluate(new Context({ a: 1, b: 2 })))
     expect(result).to.equal(false)
   })
+  it('#527 export Liquid Expression (evalValue)', async () => {
+    const liquid = new Liquid()
+    const result = await liquid.evalValue('a > b', { a: 1, b: 2 })
+    expect(result).to.equal(false)
+  })
+  it('#527 export Liquid Expression (evalValueSync)', async () => {
+    const liquid = new Liquid()
+    const result = liquid.evalValueSync('a > b', { a: 1, b: 2 })
+    expect(result).to.equal(false)
+  })
 })