feat: add find_index, has, and reject filters (#799)

* feat: add find_index, has, and reject filters

* Minor tweaks

* Change semantics of jekyllStyle, add more tests

* Some docs improvements

test/integration/filters/array.spec.ts

@@ -417,6 +417,32 @@ describe('filters/array', function () {
         - Boring sneakers
         `)
     })
+    it('should support filter with undefined target', function () {
+      return test(`{% assign typed_products = products | where: "type", notdefined %}
+        Typed products:
+        {% for product in typed_products -%}
+        - {{ product.title }}
+        {% endfor %}`, { products }, `
+        Typed products:
+        - Vacuum
+        - Spatula
+        - Television
+        - Garlic press
+        `)
+    })
+    it('should support no target', function () {
+      return test(`{% assign typed_products = products | where: "type" %}
+        Typed products:
+        {% for product in typed_products -%}
+        - {{ product.title }}
+        {% endfor %}`, { products }, `
+        Typed products:
+        - Vacuum
+        - Spatula
+        - Television
+        - Garlic press
+        `)
+    })
     it('should support nested property', async function () {
       const authors = [
         { name: 'Alice', books: { year: 2019 } },
@@ -491,7 +517,7 @@ describe('filters/array', function () {
       await test('{{objs | where: "foo", "FOO" | json}}', scope, '[]')
     })
     describe('jekyll style', () => {
-      it('should not match string with array', async () => {
+      it('should filter arrays by inclusion', async () => {
         const scope = { objs: [{ foo: ['FOO', 'bar'] }] }
         await test('{{objs | where: "foo", "FOO" | json}}', scope, '[{"foo":["FOO","bar"]}]', { jekyllWhere: true })
       })
@@ -499,6 +525,14 @@ describe('filters/array', function () {
         const scope = { pages: [{ tags: ['FOO'] }, { tags: [] }, { title: 'foo' }] }
         await test('{{pages | where: "tags", empty | json}}', scope, '[{"tags":[]}]', { jekyllWhere: true })
       })
+      it('should filter by undefined when target is omitted', async () => {
+        await test('{{products | where: "type" | map: "title" | join: ","}}', { products },
+          'Coffee mug,Limited edition sneakers,Boring sneakers', { jekyllWhere: true })
+      })
+      it('should filter plainly when target is undefined', async () => {
+        await test('{{products | where: "type", notdefined | map: "title" | join: ","}}', { products },
+          'Coffee mug,Limited edition sneakers,Boring sneakers', { jekyllWhere: true })
+      })
     })
   })
   describe('where_exp', function () {
@@ -537,6 +571,89 @@ describe('filters/array', function () {
       return test(tpl, scope, html)
     })
   })
+  describe('reject', function () {
+    const products = [
+      { title: 'Vacuum', type: 'living room' },
+      { title: 'Spatula', type: 'kitchen' },
+      { title: 'Television', type: 'living room' },
+      { title: 'Garlic press', type: 'kitchen' },
+      { title: 'Coffee mug', available: true },
+      { title: 'Limited edition sneakers', available: false },
+      { title: 'Boring sneakers', available: true }
+    ]
+    it('should support reject by property value', function () {
+      return test(`{% assign kitchen_products = products | reject: "type", "kitchen" %}
+        Kitchen products:
+        {% for product in kitchen_products -%}
+        - {{ product.title }}
+        {% endfor %}`, { products }, `
+        Kitchen products:
+        - Vacuum
+        - Television
+        - Coffee mug
+        - Limited edition sneakers
+        - Boring sneakers
+        `)
+    })
+    it('should support reject truthy property', function () {
+      return test(`{% assign unavailable_products = products | reject: "available" %}
+        Unavailable products:
+        {% for product in unavailable_products -%}
+        - {{ product.title }}
+        {% endfor %}`, { products }, `
+        Unavailable products:
+        - Vacuum
+        - Spatula
+        - Television
+        - Garlic press
+        - Limited edition sneakers
+        `)
+    })
+    it('should support reject by string property', function () {
+      return test(`{% assign untyped_products = products | reject: "type" %}
+        Untyped products:
+        {% for product in untyped_products -%}
+        - {{ product.title }}
+        {% endfor %}`, { products }, `
+        Untyped products:
+        - Coffee mug
+        - Limited edition sneakers
+        - Boring sneakers
+        `)
+    })
+    describe('jekyll style', () => {
+      it('should filter arrays by exclusion', async () => {
+        const scope = { objs: [{ foo: ['FOO', 'bar'] }, { foo: ['bar', 'baz'] }, { foo: ['FOO'] }] }
+        await test('{{objs | reject: "foo", "FOO" | json}}', scope, '[{"foo":["bar","baz"]}]', { jekyllWhere: true })
+      })
+      it('should filter by undefined when target is omitted', async () => {
+        await test('{{products | reject: "type" | map: "title" | join: ","}}', { products },
+          'Vacuum,Spatula,Television,Garlic press', { jekyllWhere: true })
+      })
+    })
+  })
+  describe('reject_exp', function () {
+    const products = [
+      { title: 'Vacuum', type: 'living room' },
+      { title: 'Spatula', type: 'kitchen' },
+      { title: 'Television', type: 'living room' },
+      { title: 'Garlic press', type: 'kitchen' },
+      { title: 'Coffee mug', available: true },
+      { title: 'Limited edition sneakers', available: false },
+      { title: 'Boring sneakers', available: true }
+    ]
+    it('should support reject by exp', function () {
+      return test(`{% assign kitchen_products = products | reject_exp: "item", "item.type != 'kitchen'" %}
+        Kitchen products:
+        {% for product in kitchen_products -%}
+        - {{ product.title }}
+        {% endfor %}`, { products }, `
+        Kitchen products:
+        - Spatula
+        - Garlic press
+        `)
+    })
+  })
   describe('group_by', function () {
     const members = [
       { graduation_year: 2003, name: 'Jay' },
@@ -616,12 +733,76 @@ describe('filters/array', function () {
         JSON.stringify(expected))
     })
   })
-  describe('find', function () {
+  describe('has', function () {
+    const members = [
+      { graduation_year: 2013, name: 'Jay' },
+      { graduation_year: 2014, name: 'John' },
+      { graduation_year: 2014, name: 'Jack', age: 13 }
+    ]
+    it('should support has with no value', function () {
+      return test(
+        `{{ members | has: "age" | json }}, {{ members | has: "height" | json }}`,
+        { members },
+        `true, false`)
+    })
+    it('should support has by property', function () {
+      return test(
+        `{{ members | has: "graduation_year", 2014 | json }}`,
+        { members },
+        `true`)
+    })
+    it('should return false if not found', function () {
+      return test(
+        `{{ members | has: "graduation_year", 2018 | json }}`,
+        { members },
+        `false`)
+    })
+    describe('jekyll style', () => {
+      it('should select array by inclusion', async () => {
+        const scope = { objs: [{ foo: ['FOO', 'bar'] }] }
+        await test('{{objs | has: "foo", "FOO" | json}}', scope, 'true', { jekyllWhere: true })
+      })
+      it('should support empty as target', async () => {
+        const scope = { pages: [{ tags: ['FOO'] }, { tags: [] }, { title: 'foo' }] }
+        await test('{{pages | has: "tags", empty | json}}', scope, 'true', { jekyllWhere: true })
+      })
+      it('should search plainly when target is undefined', async () => {
+        await test('{{members | has: "age", notdefined}}', { members }, 'true', { jekyllWhere: true })
+        await test('{{members | has: "name", notdefined}}', { members }, 'false', { jekyllWhere: true })
+      })
+    })
+  })
+  describe('has_exp', function () {
     const members = [
       { graduation_year: 2013, name: 'Jay' },
       { graduation_year: 2014, name: 'John' },
       { graduation_year: 2014, name: 'Jack' }
     ]
+    it('should support has by expression', function () {
+      return test(
+        `{{ members | has_exp: "item", "item.graduation_year == 2014" | json }}`,
+        { members },
+        `true`)
+    })
+    it('should return false if not found', function () {
+      return test(
+        `{{ members | has_exp: "item", "item.graduation_year == 2018" | json }}`,
+        { members },
+        `false`)
+    })
+  })
+  describe('find', function () {
+    const members = [
+      { graduation_year: 2013, name: 'Jay' },
+      { graduation_year: 2014, name: 'John' },
+      { graduation_year: 2014, name: 'Jack', age: 13 }
+    ]
+    it('should support find with no value', function () {
+      return test(
+        `{{ members | find: "age" | json }}`,
+        { members },
+        `{"graduation_year":2014,"name":"Jack","age":13}`)
+    })
     it('should support find by property', function () {
       return test(
         `{{ members | find: "graduation_year", 2014 | json }}`,
@@ -634,6 +815,24 @@ describe('filters/array', function () {
         { members },
         ``)
     })
+    describe('jekyll style', () => {
+      it('should select array by inclusion', async () => {
+        const scope = { objs: [{ foo: ['FOO', 'bar'] }] }
+        await test('{{objs | find: "foo", "FOO" | json}}', scope, '{"foo":["FOO","bar"]}', { jekyllWhere: true })
+      })
+      it('should support empty as target', async () => {
+        const scope = { pages: [{ tags: ['FOO'] }, { tags: [] }, { title: 'foo' }] }
+        await test('{{pages | find: "tags", empty | json}}', scope, '{"tags":[]}', { jekyllWhere: true })
+      })
+      it('should search plainly when target is undefined', async () => {
+        await test(
+          '{{members | find: "age", notdefined | json}}',
+          { members },
+          '{"graduation_year":2013,"name":"Jay"}',
+          { jekyllWhere: true })
+        await test('{{members | find: "name", notdefined | json}}', { members }, '', { jekyllWhere: true })
+      })
+    })
   })
   describe('find_exp', function () {
     const members = [
@@ -654,4 +853,62 @@ describe('filters/array', function () {
         ``)
     })
   })
+  describe('find_index', function () {
+    const members = [
+      { graduation_year: 2013, name: 'Jay' },
+      { graduation_year: 2014, name: 'John' },
+      { graduation_year: 2014, name: 'Jack', age: 13 }
+    ]
+    it('should support find_index with no value', function () {
+      return test(
+        `{{ members | find_index: "age" | json }}`,
+        { members },
+        `2`)
+    })
+    it('should support find_index by property', function () {
+      return test(
+        `{{ members | find_index: "graduation_year", 2014 | json }}`,
+        { members },
+        `1`)
+    })
+    it('should render none if not found', function () {
+      return test(
+        `{{ members | find_index: "graduation_year", 2018 | json }}`,
+        { members },
+        ``)
+    })
+    describe('jekyll style', () => {
+      it('should select array by inclusion', async () => {
+        const scope = { objs: [{ foo: ['FOO', 'bar'] }] }
+        await test('{{objs | find_index: "foo", "FOO" | json}}', scope, '0', { jekyllWhere: true })
+      })
+      it('should support empty as target', async () => {
+        const scope = { pages: [{ tags: ['FOO'] }, { tags: [] }, { title: 'foo' }] }
+        await test('{{pages | find_index: "tags", empty | json}}', scope, '1', { jekyllWhere: true })
+      })
+      it('should search plainly when target is undefined', async () => {
+        await test('{{members | find_index: "age", notdefined | json}}', { members }, '0', { jekyllWhere: true })
+        await test('{{members | find_index: "name", notdefined | json}}', { members }, '', { jekyllWhere: true })
+      })
+    })
+  })
+  describe('find_index_exp', function () {
+    const members = [
+      { graduation_year: 2013, name: 'Jay' },
+      { graduation_year: 2014, name: 'John' },
+      { graduation_year: 2014, name: 'Jack' }
+    ]
+    it('should support find_index by expression', function () {
+      return test(
+        `{{ members | find_index_exp: "item", "item.graduation_year == 2014" | json }}`,
+        { members },
+        `1`)
+    })
+    it('should render none if not found', function () {
+      return test(
+        `{{ members | find_index_exp: "item", "item.graduation_year == 2018" | json }}`,
+        { members },
+        ``)
+    })
+  })
 })