Implement defer

Closes #8086
Closes #12589

tpl/templates/defer_integration_test.go

@@ -0,0 +1,202 @@
+// Copyright 2024 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 templates_test
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+
+	"github.com/gohugoio/hugo/hugolib"
+)
+
+const deferFilesCommon = `
+-- hugo.toml --
+disableLiveReload = true
+disableKinds = ["taxonomy", "term", "rss", "sitemap", "robotsTXT", "404", "section"]
+[languages]
+[languages.en]
+weight = 1
+[languages.nn]
+weight = 2
+-- i18n/en.toml --
+[hello]
+other = "Hello"
+-- i18n/nn.toml --
+[hello]
+other = "Hei"
+-- content/_index.en.md --
+---
+title: "Home"
+outputs: ["html", "amp"]
+---
+-- content/_index.nn.md --
+---
+title: "Heim"
+outputs: ["html", "amp"]
+---
+-- assets/mytext.txt --
+Hello.
+-- layouts/baseof.html --
+HTML|{{ block "main" . }}{{ end }}$
+-- layouts/index.html --
+{{ define "main" }}
+EDIT_COUNTER_OUTSIDE_0
+{{ .Store.Set "hello" "Hello" }}
+{{ $data := dict "page" . }}
+{{ with (templates.Defer (dict "data" $data) ) }}
+{{ $mytext := resources.Get "mytext.txt" }}
+REPLACE_ME|Title: {{ .page.Title }}|{{ .page.RelPermalink }}|Hello: {{ T "hello" }}|Hello Store: {{ .page.Store.Get "hello" }}|Mytext: {{ $mytext.Content }}|
+EDIT_COUNTER_DEFER_0
+{{ end }}$
+{{ end }}
+-- layouts/index.amp.html --
+AMP.
+{{ $data := dict "page" . }}
+{{ with (templates.Defer (dict "data" $data) ) }}Title AMP: {{ .page.Title }}|{{ .page.RelPermalink }}|Hello: {{ T "hello" }}{{ end }}$
+
+`
+
+func TestDeferBasic(t *testing.T) {
+	t.Parallel()
+
+	b := hugolib.Test(t, deferFilesCommon)
+
+	b.AssertFileContent("public/index.html", "Title: Home|/|Hello: Hello|Hello Store: Hello|Mytext: Hello.|")
+	b.AssertFileContent("public/amp/index.html", "Title AMP: Home|/amp/|Hello: Hello")
+	b.AssertFileContent("public/nn/index.html", "Title: Heim|/nn/|Hello: Hei")
+	b.AssertFileContent("public/nn/amp/index.html", "Title AMP: Heim|/nn/amp/|Hello: Hei")
+}
+
+func TestDeferRepeatedBuildsEditOutside(t *testing.T) {
+	t.Parallel()
+
+	b := hugolib.TestRunning(t, deferFilesCommon)
+
+	for i := 0; i < 5; i++ {
+		old := fmt.Sprintf("EDIT_COUNTER_OUTSIDE_%d", i)
+		new := fmt.Sprintf("EDIT_COUNTER_OUTSIDE_%d", i+1)
+		b.EditFileReplaceAll("layouts/index.html", old, new).Build()
+		b.AssertFileContent("public/index.html", new)
+	}
+}
+
+func TestDeferRepeatedBuildsEditDefer(t *testing.T) {
+	t.Parallel()
+
+	b := hugolib.TestRunning(t, deferFilesCommon)
+
+	for i := 0; i < 8; i++ {
+		old := fmt.Sprintf("EDIT_COUNTER_DEFER_%d", i)
+		new := fmt.Sprintf("EDIT_COUNTER_DEFER_%d", i+1)
+		b.EditFileReplaceAll("layouts/index.html", old, new).Build()
+		b.AssertFileContent("public/index.html", new)
+	}
+}
+
+func TestDeferErrorParse(t *testing.T) {
+	t.Parallel()
+
+	b, err := hugolib.TestE(t, strings.ReplaceAll(deferFilesCommon, "Title AMP: {{ .page.Title }}", "{{ .page.Title }"))
+
+	b.Assert(err, qt.Not(qt.IsNil))
+	b.Assert(err.Error(), qt.Contains, `index.amp.html:3: unexpected "}" in operand`)
+}
+
+func TestDeferErrorRuntime(t *testing.T) {
+	t.Parallel()
+
+	b, err := hugolib.TestE(t, strings.ReplaceAll(deferFilesCommon, "Title AMP: {{ .page.Title }}", "{{ .page.Titles }}"))
+
+	b.Assert(err, qt.Not(qt.IsNil))
+	b.Assert(err.Error(), qt.Contains, filepath.FromSlash(`/layouts/index.amp.html:3:57`))
+	b.Assert(err.Error(), qt.Contains, `execute of template failed: template: index.amp.html:3:57: executing at <.page.Titles>: can't evaluate field Titles`)
+}
+
+func TestDeferEditDeferBlock(t *testing.T) {
+	t.Parallel()
+
+	b := hugolib.TestRunning(t, deferFilesCommon)
+	b.AssertRenderCountPage(4)
+	b.EditFileReplaceAll("layouts/index.html", "REPLACE_ME", "Edited.").Build()
+	b.AssertFileContent("public/index.html", "Edited.")
+	b.AssertRenderCountPage(2)
+}
+
+//
+
+func TestDeferEditResourceUsedInDeferBlock(t *testing.T) {
+	t.Parallel()
+
+	b := hugolib.TestRunning(t, deferFilesCommon)
+	b.AssertRenderCountPage(4)
+	b.EditFiles("assets/mytext.txt", "Mytext Hello Edited.").Build()
+	b.AssertFileContent("public/index.html", "Mytext Hello Edited.")
+	b.AssertRenderCountPage(2)
+}
+
+func TestDeferMountPublic(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+[module]
+[[module.mounts]]
+source = "content"
+target = "content"
+[[module.mounts]]
+source = "layouts"
+target = "layouts"
+[[module.mounts]]
+source = 'public'
+target = 'assets/public'
+disableWatch = true
+-- layouts/index.html --
+Home.
+{{ $mydata := dict "v1" "v1value" }}
+{{ $json := resources.FromString "mydata/data.json" ($mydata | jsonify ) }}
+{{ $nop := $json.RelPermalink }}
+{{ with (templates.Defer (dict "key" "foo")) }}
+	  {{ $jsonFilePublic := resources.Get "public/mydata/data.json" }}
+	  {{ with  $jsonFilePublic }}
+      {{ $m := $jsonFilePublic | transform.Unmarshal }}
+	  v1: {{ $m.v1 }}
+	  {{ end }}
+{{ end }}
+`
+
+	b := hugolib.Test(t, files)
+
+	b.AssertFileContent("public/index.html", "v1: v1value")
+}
+
+func TestDeferFromContentAdapterShouldFail(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+-- content/_content.gotmpl --
+{{ with (templates.Defer (dict "key" "foo")) }}
+ Foo.
+{{ end }}
+`
+
+	b, err := hugolib.TestE(t, files)
+
+	b.Assert(err, qt.Not(qt.IsNil))
+	b.Assert(err.Error(), qt.Contains, "error calling Defer: this method cannot be called before the site is fully initialized")
+}