[GSOC][PATCH] userdiff: add builtin patterns for JavaScript.

[Sergius Nyah <sergiusnyah@xxxxxxxxx>]

This commit introduces builtin patterns for JavaScript in userdiff.

It adds a new test case in t4018-diff-funcname.sh to verify the enhanced
JavaScript function detection in Git diffs.

Signed-off-by: Sergius Justus Chesami Nyah <sergiusnyah@xxxxxxxxx>
---
userdiff.c | 17 +++++++++++++++--
t/t4018-diff-funcname.sh | 25 ++++++++-
2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/userdiff.c b/userdiff.c
index e399543823..12e31ff14d 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -18,40 +16,19 @@
#include "git-compat-util.h"
#include "config.h"
#include "userdiff.h"
#include "strbuf.h"

PATTERNS("javascript",
      /* Looks for lines that start with optional whitespace, followed
      * by 'function'* and any characters (for function declarations),
      * or valid JavaScript identifiers, equals sign '=', 'function' keyword
      * and any characters (for function expressions).
      * Also considers functions defined inside blocks with '{...}'.
      */
      "^[ \t]*(function[ \t]*.*|[a-zA-Z_$][0-9a-zA-Z_$]*[ \t]*=[ \t]*function[ \t]*.*|(\\{[ \t]*)?)\n",
      /* This pattern matches JavaScript identifiers */
      "[a-zA-Z_$][0-9a-zA-Z_$]*"
      "|[-+0-9.eE]+|0[xX][0-9a-fA-F]+"
      "|[-+*/<>%&^|=!:]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\|"),

diff --git a/t/t4018-diff-funcname.sh b/t/t4018-diff-funcname.sh
index 43593866bc..9c3b80665e 100644
--- a/t/t4018-diff-funcname.sh
+++ b/t/t4018-diff-funcname.sh
@@ -18,40 +16,19 @@
test_expect_success 'identify builtin patterns in Javascript' '
    # setup
    echo "function myFunction() { return true; }" > test.js &&
    echo "var myVar = function() { return false; }" >> test.js &&
    git add test.js &&
    git commit -m "add test.js" &&

    # modify the file
    echo "function myFunction() { return false; }" > test.js &&
    echo "var myVar = function() { return true; }" >> test.js &&

    # command under test
    git diff >output &&

    # check results
    test_i18ngrep "function myFunction() { return true; }" output &&
    test_i18ngrep "function myFunction() { return false; }" output &&
    test_i18ngrep "var myVar = function() { return false; }" output &&
    test_i18ngrep "var myVar = function() { return true; }" output
'

test_done
--
2.43.2