Subject: [PATCH] userdiff: expand detected chunk headers for css

From: "Sohom Datta via GitGitGadget" <[email-masked]>
Date: Wed, 07 Oct 2020 09:25:26 +0000

From: Sohom <[email-masked]>

Added support for classes, ids, :root selectors
as well as @-based statements (ex: @page, @media
and @keyframes ).

Also added tests for the same.

Signed-off-by: Sohom Datta <[email-masked]>
---
    userdiff: Expand detected chunk headers for css
    
    Currently, the regex used for the CSS builtin diff driver in git is only
    able to show chunk headers for lines that start with a number, a letter
    or an underscore.
    
    However, the regex fails to detect classes (starts with a .), ids
    (starts with a #), :root and attribute-value based selectors (for
    example [class*="col-"]), as well as @based block-level statements like 
    @page,@keyframes and @media since all of them, start with a special
    character.
    
    I've modified the chunk header CSS regex so that it is able to detect
    the statements above and add them to the chunk header.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-866%2Fsohomdatta1%2Fcss-userdiff-fix-test-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-866/sohomdatta1/css-userdiff-fix-test-v1
Pull-Request: https://github.com/git/git/pull/866

 t/t4018/css-attribute-value-selector |  4 ++++
 t/t4018/css-block-level-@-statements | 10 ++++++++++
 t/t4018/css-class-selector           |  4 ++++
 t/t4018/css-id-selector              |  4 ++++
 t/t4018/css-root-selector            |  4 ++++
 userdiff.c                           |  2 +-
 6 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 t/t4018/css-attribute-value-selector
 create mode 100644 t/t4018/css-block-level-@-statements
 create mode 100644 t/t4018/css-class-selector
 create mode 100644 t/t4018/css-id-selector
 create mode 100644 t/t4018/css-root-selector

diff --git a/t/t4018/css-attribute-value-selector b/t/t4018/css-attribute-value-selector
new file mode 100644
index 0000000000..918256b20c
--- /dev/null
+++ b/t/t4018/css-attribute-value-selector
@@ -0,0 +1,4 @@
+[class*="RIGHT"] {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-block-level-@-statements b/t/t4018/css-block-level-@-statements
new file mode 100644
index 0000000000..d6755f2f3d
--- /dev/null
+++ b/t/t4018/css-block-level-@-statements
@@ -0,0 +1,10 @@
+@keyframes RIGHT {
+    from {
+        background : #000;
+        border : 10px ChangeMe #C6C6C6;
+    }
+    to {
+        background : #fff;
+        border : 10px solid #C6C6C6;
+    }
+}
diff --git a/t/t4018/css-class-selector b/t/t4018/css-class-selector
new file mode 100644
index 0000000000..f790a0062f
--- /dev/null
+++ b/t/t4018/css-class-selector
@@ -0,0 +1,4 @@
+.RIGHT {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-id-selector b/t/t4018/css-id-selector
new file mode 100644
index 0000000000..17c5111052
--- /dev/null
+++ b/t/t4018/css-id-selector
@@ -0,0 +1,4 @@
+#RIGHT {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-root-selector b/t/t4018/css-root-selector
new file mode 100644
index 0000000000..22b958e369
--- /dev/null
+++ b/t/t4018/css-root-selector
@@ -0,0 +1,4 @@
+:RIGHT {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/userdiff.c b/userdiff.c
index fde02f225b..49c9771891 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -200,7 +200,7 @@ PATTERNS("csharp",
 	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
 IPATTERN("css",
 	 "![:;][[:space:]]*$\n"
-	 "^[_a-z0-9].*$",
+	 "^(([_a-z0-9]|[:[@.#][_a-z0-9]).*)$",
 	 /* -- */
 	 /*
 	  * This regex comes from W3C CSS specs. Should theoretically also

base-commit: d98273ba77e1ab9ec755576bc86c716a97bf59d7
-- 
gitgitgadget