From f14261f6ff0ae8db70f543ba2230633d0f95d3da Mon Sep 17 00:00:00 2001
From: Liam Bigelow <liam@cloudcannon.com>
Date: Thu, 3 Feb 2022 09:59:11 +1300
Subject: [PATCH] fix: match hugo's (bizzare) handling of short markdown
 strings

---
 .../helpers/bookshop_modified_content.go      | 28 +++++++++++++++++++
 .../hugo-renderer/tpl/transform/transform.go  |  3 ++
 .../hugo_bookshop_live_filters.feature        | 15 ++++++++--
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/javascript-modules/engines/hugo-engine/hugo-renderer/helpers/bookshop_modified_content.go b/javascript-modules/engines/hugo-engine/hugo-renderer/helpers/bookshop_modified_content.go
index 2dcc5035..c38c8560 100644
--- a/javascript-modules/engines/hugo-engine/hugo-renderer/helpers/bookshop_modified_content.go
+++ b/javascript-modules/engines/hugo-engine/hugo-renderer/helpers/bookshop_modified_content.go
@@ -18,6 +18,7 @@
 package helpers
 
 import (
+	"bytes"
 	"html/template"
 	"strings"
 	"unicode"
@@ -25,6 +26,13 @@ import (
 	bp "github.com/gohugoio/hugo/bufferpool"
 )
 
+var (
+	openingPTag        = []byte("<p>")
+	closingPTag        = []byte("</p>")
+	paragraphIndicator = []byte("<p")
+	closingIndicator   = []byte("</")
+)
+
 var stripHTMLReplacer = strings.NewReplacer("\n", " ", "</p>", "\n", "<br>", "\n", "<br />", "\n")
 
 // StripHTML accepts a string, strips out all HTML tags and returns it.
@@ -68,3 +76,23 @@ func StripHTML(s string) string {
 func BytesToHTML(b []byte) template.HTML {
 	return template.HTML(string(b))
 }
+
+// TrimShortHTML removes the <p>/</p> tags from HTML input in the situation
+// where said tags are the only <p> tags in the input and enclose the content
+// of the input (whitespace excluded).
+// Bookshop: Changed this to _not_ be a method of *ContentSpec
+func TrimShortHTML(input []byte) []byte {
+	firstOpeningP := bytes.Index(input, paragraphIndicator)
+	lastOpeningP := bytes.LastIndex(input, paragraphIndicator)
+
+	lastClosingP := bytes.LastIndex(input, closingPTag)
+	lastClosing := bytes.LastIndex(input, closingIndicator)
+
+	if firstOpeningP == lastOpeningP && lastClosingP == lastClosing {
+		input = bytes.TrimSpace(input)
+		input = bytes.TrimPrefix(input, openingPTag)
+		input = bytes.TrimSuffix(input, closingPTag)
+		input = bytes.TrimSpace(input)
+	}
+	return input
+}
diff --git a/javascript-modules/engines/hugo-engine/hugo-renderer/tpl/transform/transform.go b/javascript-modules/engines/hugo-engine/hugo-renderer/tpl/transform/transform.go
index 548f4a24..f46d6b10 100644
--- a/javascript-modules/engines/hugo-engine/hugo-renderer/tpl/transform/transform.go
+++ b/javascript-modules/engines/hugo-engine/hugo-renderer/tpl/transform/transform.go
@@ -99,6 +99,9 @@ func (ns *Namespace) Markdownify(s interface{}) (template.HTML, error) {
 	// This includes using a different (smaller) markdown implementation.
 	output := markdown.ToHTML([]byte(ss), nil, nil)
 
+	// Strip if this is a short inline type of text.
+	output = helpers.TrimShortHTML(output)
+
 	return helpers.BytesToHTML(output), nil
 }
 
diff --git a/javascript-modules/integration-tests/features/hugo/live_editing/hugo_bookshop_live_filters.feature b/javascript-modules/integration-tests/features/hugo/live_editing/hugo_bookshop_live_filters.feature
index 6561e4cf..82497954 100644
--- a/javascript-modules/integration-tests/features/hugo/live_editing/hugo_bookshop_live_filters.feature
+++ b/javascript-modules/integration-tests/features/hugo/live_editing/hugo_bookshop_live_filters.feature
@@ -18,11 +18,12 @@ Feature: Hugo Bookshop CloudCannon Live Editing Filters and Functions
   Scenario: Bookshop live renders markdown
     Given a component-lib/components/beetroot/beetroot.hugo.html file containing:
       """
-      <div><code>{{ .md | markdownify }}</code></div>
+      <div>{{ .md | markdownify }}</div>
       """
     Given [front_matter]:
       """
       md: title
+      multi_md: title
       """
     And a site/content/_index.md file containing:
       """
@@ -36,6 +37,9 @@ Feature: Hugo Bookshop CloudCannon Live Editing Filters and Functions
       <body>
       {{ partial "bookshop_bindings" `(dict "md" .Params.md )` }}
       {{ partial "bookshop" (slice "beetroot" (dict "md" .Params.md )) }}
+
+      {{ partial "bookshop_bindings" `(dict "md" .Params.multi_md )` }}
+      {{ partial "bookshop" (slice "beetroot" (dict "md" .Params.multi_md )) }}
       </body>
       </html>
       """
@@ -43,8 +47,15 @@ Feature: Hugo Bookshop CloudCannon Live Editing Filters and Functions
     When 🌐 CloudCannon pushes new yaml:
       """
       md: "**bold** title"
+      multi_md: >-
+        # Hello  
+
+        World
       """
     Then 🌐 There should be no errors
     *    🌐 There should be no logs
-    *    🌐 The selector code should match "<p><strong>bold</strong> title</p>"
+    # Hugo strips single <p> tags
+    *    🌐 The selector div:nth-of-type(1) should match "<strong>bold</strong> title"
+    *    🌐 The selector div:nth-of-type(2) should match "<h1>Hello</h1>"
+    *    🌐 The selector div:nth-of-type(2) should match "<p>World</p>"
   
\ No newline at end of file