hugo/tpl/collections/append_test.go
Bjørn Erik Pedersen e27fd4c1b8 tpl/collections: Add collections.Append
Before this commit you would typically use `.Scratch.Add` to manually create slices in a loop.

With variable overwrite in Go 1.11, we can do better. This commit adds the `append` template func.

A made-up example:

```bash
{{ $p1 := index .Site.RegularPages 0 }}{{ $p2 := index .Site.RegularPages 1 }}
{{ $pages := slice }}
{{ if true }}
  {{ $pages = $pages | append $p2 $p1 }}
{{ end }}
```

Note that with 2 slices as arguments, the two examples below will give the same result:

```bash
{{ $s1 := slice "a" "b" | append (slice "c" "d") }}
{{ $s2 := slice "a" "b" | append "c" "d" }}
```

Both of the above will give `[]string{a, b, c, d}`.

This commit also improves the type handling in the `slice` template function. Now `slice "a" "b"` will give a `[]string` slice. The old behaviour was to return a `[]interface{}`.

Fixes #5190
2018-09-14 10:12:08 +02:00

77 lines
2.2 KiB
Go

// Copyright 2018 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package collections
import (
"fmt"
"reflect"
"testing"
"github.com/alecthomas/assert"
"github.com/gohugoio/hugo/deps"
"github.com/stretchr/testify/require"
)
func TestAppend(t *testing.T) {
t.Parallel()
ns := New(&deps.Deps{})
for i, test := range []struct {
start interface{}
addend []interface{}
expected interface{}
}{
{[]string{"a", "b"}, []interface{}{"c"}, []string{"a", "b", "c"}},
{[]string{"a", "b"}, []interface{}{"c", "d", "e"}, []string{"a", "b", "c", "d", "e"}},
{[]string{"a", "b"}, []interface{}{[]string{"c", "d", "e"}}, []string{"a", "b", "c", "d", "e"}},
{nil, []interface{}{"a", "b"}, []string{"a", "b"}},
{nil, []interface{}{nil}, []interface{}{nil}},
{tstSlicers{&tstSlicer{"a"}, &tstSlicer{"b"}},
[]interface{}{&tstSlicer{"c"}},
tstSlicers{&tstSlicer{"a"}, &tstSlicer{"b"}, &tstSlicer{"c"}}},
{&tstSlicers{&tstSlicer{"a"}, &tstSlicer{"b"}},
[]interface{}{&tstSlicer{"c"}},
tstSlicers{&tstSlicer{"a"},
&tstSlicer{"b"},
&tstSlicer{"c"}}},
// Errors
{"", []interface{}{[]string{"a", "b"}}, false},
{[]string{"a", "b"}, []interface{}{}, false},
// No string concatenation.
{"ab",
[]interface{}{"c"},
false},
} {
errMsg := fmt.Sprintf("[%d]", i)
args := append(test.addend, test.start)
result, err := ns.Append(args...)
if b, ok := test.expected.(bool); ok && !b {
require.Error(t, err, errMsg)
continue
}
require.NoError(t, err, errMsg)
if !reflect.DeepEqual(test.expected, result) {
t.Fatalf("%s got\n%T: %v\nexpected\n%T: %v", errMsg, result, result, test.expected, test.expected)
}
}
assert.Len(t, ns.Slice(), 0)
}