implement lenientIf for the unless tag, too

docs/source/tutorials/options.md

@@ -89,7 +89,7 @@ it defaults to false.  For example, when set to true, a blank string would evalu
 
 **strictVariables** is used to assert variable existence.  If set to `false`, undefined variables will be rendered as empty string.  Otherwise, undefined variables will cause a render exception. Defaults to `false`.
 
-**lenientIf** modifies the behavior of `strictVariables` to allow handling optional variables. If set to `true`, an undefined variable will *not* cause an exception in the following two situations: a) it is the condition to an `if` or `elsif` tag; b) it occurs right before a `default` filter. Irrelevant if `strictVariables` is not set. Defaults to `false`.
+**lenientIf** modifies the behavior of `strictVariables` to allow handling optional variables. If set to `true`, an undefined variable will *not* cause an exception in the following two situations: a) it is the condition to an `if`, `elsif`, or `unless` tag; b) it occurs right before a `default` filter. Irrelevant if `strictVariables` is not set. Defaults to `false`.
 
 {% note info Non-existent Tags %}
 Non-existent tags always throw errors during pasrsing and this behaviour can not be customized.

src/builtin/tags/unless.ts

@@ -22,7 +22,7 @@ export default {
 
   render: function * (ctx: Context, emitter: Emitter) {
     const r = this.liquid.renderer
-    const cond = yield new Expression(this.cond).value(ctx)
+    const cond = yield new Expression(this.cond, ctx.opts.lenientIf).value(ctx)
     yield (isFalsy(cond, ctx)
       ? r.renderTemplates(this.templates, ctx, emitter)
       : r.renderTemplates(this.elseTemplates, ctx, emitter))

src/liquid-options.ts

@@ -19,7 +19,7 @@ export interface LiquidOptions {
   strictFilters?: boolean;
   /** Whether or not to assert variable existence.  If set to `false`, undefined variables will be rendered as empty string.  Otherwise, undefined variables will cause an exception. Defaults to `false`. */
   strictVariables?: boolean;
-  /** Modifies the behavior of `strictVariables`. If set, a single undefined variable will *not* cause an exception in the context of the `if` tag and the `default` filter. Instead, it will evaluate to `false` and `null`, respectively. Irrelevant if `strictVariables` is not set. Defaults to `false`. **/
+  /** Modifies the behavior of `strictVariables`. If set, a single undefined variable will *not* cause an exception in the context of the `if`/`elsif`/`unless` tag and the `default` filter. Instead, it will evaluate to `false` and `null`, respectively. Irrelevant if `strictVariables` is not set. Defaults to `false`. **/
   lenientIf?: boolean;
   /** Strip blank characters (including ` `, `\t`, and `\r`) from the right of tags (`{% %}`) until `\n` (inclusive). Defaults to `false`. */
   trimTagRight?: boolean;

test/integration/liquid/strict.ts

@@ -45,7 +45,12 @@ describe('LiquidOptions#strict*', function () {
       const html = await engine.render(tpl, {'defined3': 'bla'}, strictLenientOpts)
       return expect(html).to.equal('bla')
     })
-    it('should still throw with an undefined variable in an expression', function () {
+    it('should not throw in `unless` with a single variable', async function () {
+      const tpl = engine.parse('before{% unless notdefined %}X{% else %}{{notdefined}}{% endunless %}after')
+      const html = await engine.render(tpl, ctx, strictLenientOpts)
+      return expect(html).to.equal('beforeXafter')
+    })
+    it('should still throw with an undefined variable in a compound `if` expression', function () {
       const tpl = engine.parse('{% if notdefined == 15 %}a{% endif %}')
       const fhtml = engine.render(tpl, ctx, strictLenientOpts)
       return expect(fhtml).to.be.rejectedWith(/undefined variable: notdefined/)