Shell: Add some tests for brace expansions

Author: https://github.com/alimpfard
Commit: https://github.com/SerenityOS/serenity/commit/f7dbd14a87b
Pull-request: https://github.com/SerenityOS/serenity/pull/3835
Issue: https://github.com/SerenityOS/serenity/issues/3832
Reviewed-by: https://github.com/bugaevc
Reviewed-by: https://github.com/linusg

Shell/Tests/brace-exp.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+setopt --verbose
+
+fail() {
+    echo $*
+    exit 1
+}
+
+test "$(echo {a,b,})" = "a b " || fail normal brace expansion with one empty slot
+test "$(echo {a,,b})" = "a  b" || fail normal brace expansion with one empty slot
+test "$(echo {a,,,b})" = "a   b" || fail normal brace expansion with two empty slots
+test "$(echo {a,b,,})" = "a b  " || fail normal brace expansion with two empty slots
+
+test "$(echo {a..c})" = "a b c" || fail range brace expansion, alpha
+test "$(echo {0..3})" = "0 1 2 3" || fail range brace expansion, number
+test "$(echo {😂..😄})" = "😂 😃 😄" || fail range brace expansion, unicode codepoint
+
+# Make sure that didn't mess with dots and commas in normal barewords
+test .. = ".." || fail range brace expansion delimiter affects normal barewords
+test , = "," || fail normal brace expansion delimiter affects normal barewords