fix: in conditionals, don't render anything after an else branch (#671)

* fix: only render the first 'else' template in the case of multiples

* fix: empty else block and cases with when conditions

* fix: don't render elsif after else

* chore: Update src/tags/unless.ts

* chore: Update src/tags/if.ts

* chore: Update src/tags/case.ts

---------

Co-authored-by: Jun Yang <[email protected]>

test/integration/tags/case.spec.ts

@@ -91,4 +91,32 @@ describe('tags/case', function () {
     const html = await liquid.parseAndRender(src)
     return expect(html).toBe('and or or')
   })
+  it('should not render anything after an else branch', async function () {
+    const html = await liquid.parseAndRenderSync('{% assign value = "this" %}' +
+    '{% case true %}' +
+      '{% when false %}don\'t show' +
+      '{% else %}show {{ value }}' +
+      '{% else %}don\'t show' +
+    '{% endcase %}', {})
+    expect(html).toEqual('show this')
+  })
+  it('should not render anything after an else branch even when first else branch is empty', async function () {
+    const html = await liquid.parseAndRenderSync('{% case true %}' +
+      '{% when false %}don\'t show' +
+      '{% else %}' +
+      '{% else %}don\'t show' +
+    '{% endcase %}', {})
+    expect(html).toEqual('')
+  })
+  it('should not render anything after an else branch even when there are \'when\' conditions', () => {
+    const engine = new Liquid()
+    const result = engine.parseAndRenderSync('{% assign value = "this" %}' +
+    '{% case true -%}' +
+      '{% when false -%}don\'t show' +
+      '{% else %}show {{ value }}' +
+      '{% else %}don\'t show' +
+      '{%- when true -%}don\'t show' +
+    '{%- endcase %}', {})
+    expect(result).toEqual('show this')
+  })
 })

test/integration/tags/if.spec.ts

@@ -143,4 +143,12 @@ describe('tags/if', function () {
     const html = await liquid.parseAndRender(src, scope)
     return expect(html).toBe('success')
   })
+  it('should not render anything after an else branch even when first else branch is empty', () => {
+    const engine = new Liquid()
+    const result = engine.parseAndRenderSync('{% if false %}don\'t show' +
+      '{% else %}' +
+      '{% else %}don\'t show' +
+    '%{% endif %}', {})
+    expect(result).toEqual('')
+  })
 })

test/integration/tags/unless.spec.ts

@@ -47,6 +47,29 @@ describe('tags/unless', function () {
       Inside wonderland
       After wonderland`)
   })
+  it('should not render anything after an else branch', async function () {
+    const html = await liquid.parseAndRenderSync('{% assign value = "this" %}' +
+      '{% unless true %}don\'t show' +
+      '{% else %}show {{ value }}' +
+      '{% else %}don\'t show' +
+    '{% endunless %}', {})
+    expect(html).toEqual('show this')
+  })
+  it('should not render anything after an else branch even when first else branch is empty', async function () {
+    const html = await liquid.parseAndRenderSync('{% unless true %}don\'t show' +
+      '{% else %}' +
+      '{% else %}don\'t show' +
+    '{% endunless %}', {})
+    expect(html).toEqual('')
+  })
+  it('should not render an elseif after an else branch', () => {
+    const engine = new Liquid()
+    const result = engine.parseAndRenderSync('{% unless true %}don\'t show' +
+      '{% else %}show' +
+      '{% elsif true %}don\'t show' +
+    '{% endunless %}', {})
+    expect(result).toEqual('show')
+  })
 
   describe('sync support', function () {
     it('should render else when predicate yields true', function () {