test(zutil): set up test; add tests

.github/workflows/check.yml

@@ -31,6 +31,13 @@ jobs:
         package-file: .github/tl_package
         update-all-packages: true
 
+    - name: Run zutil tests
+      run: |
+        cd zutil
+        l3build check \
+          --halt-on-error--show-saves \
+          ${{ matrix.option }}
+
     - name: Run tabularray tests
       run: |
         cd tabularray

zutil/testfiles/zutil-001.lvt

@@ -0,0 +1,10 @@
+\input{regression-test}
+\documentclass{article}
+
+\ExplSyntaxOn
+\debug_on:n { check-declarations , check-expressions, deprecation }
+\ExplSyntaxOff
+
+\START
+\usepackage{zutil}
+\END

zutil/testfiles/zutil-001.tlg

@@ -0,0 +1,5 @@
+This is a generated file for the l3build validation system.
+Don't change this file in any respect.
+(zutil.sty
+Package: zutil ....-..-.. v... Z's utilities, l3seq part
+)

zutil/testfiles/zutil-seq-001.lvt

@@ -0,0 +1,33 @@
+\input{regression-test}
+\documentclass{minimal}
+
+\usepackage{zutil}
+
+\ExplSyntaxOn
+
+\debug_on:n { check-declarations , deprecation }
+
+\START
+
+% based on l3kernel test for \seq_set_split_keep_spaces:Nnn,
+% from l3kernel/testfiles/m3seq004.lvt
+\TEST{zutil_seq_set_split_keep_braces:Nnn}{
+  \zutil_seq_set_split_keep_braces:Nnn \l_tmpa_seq { | } { }
+  \seq_log:N \l_tmpa_seq
+  \zutil_seq_set_split_keep_braces:Nnn \l_tmpa_seq { , } { a, }
+  \seq_log:N \l_tmpa_seq
+  \zutil_seq_set_split_keep_braces:Nnn \l_tmpa_seq { , } { a~,~b }
+  \seq_log:N \l_tmpa_seq
+  \zutil_seq_set_split_keep_braces:Nnn \l_tmpa_seq { | }
+    { ~ a | b | ~c~ | {|} | ~{~|{}~} | d ~ }
+  \seq_log:N \l_tmpa_seq
+  \zutil_seq_set_split_keep_braces:Nnn \l_tmpa_seq { ~ }
+    { Hello,~world,~my~name~is~LaTeX! }
+  \seq_log:N \l_tmpa_seq
+  \zutil_seq_set_split_keep_braces:Nnn \l_tmpa_seq { } { abcdefghijklm }
+  \seq_log:N \l_tmpa_seq
+}
+
+\ExplSyntaxOff
+
+\END

zutil/testfiles/zutil-seq-001.tlg

@@ -0,0 +1,43 @@
+This is a generated file for the l3build validation system.
+Don't change this file in any respect.
+============================================================
+TEST 1: zutil_seq_set_split_keep_braces:Nnn
+============================================================
+The sequence \l_tmpa_seq contains the items (without outer braces):
+>  {}.
+The sequence \l_tmpa_seq contains the items (without outer braces):
+>  {a}
+>  {}.
+The sequence \l_tmpa_seq contains the items (without outer braces):
+>  {a}
+>  {b}.
+The sequence \l_tmpa_seq contains the items (without outer braces):
+>  {a}
+>  {b}
+>  {c}
+>  {{|}}
+>  {{ |{} }}
+>  {d}.
+The sequence \l_tmpa_seq contains the items (without outer braces):
+>  {Hello,}
+>  {world,}
+>  {my}
+>  {name}
+>  {is}
+>  {LaTeX!}.
+! Package zutil Error: Empty delimiter is not supported in \zutil_seq_set_split_keep_braces:Nnn .
+(zutil)                The existing definition of '\l_tmpa_seq ' will not be altered.
+Type <return> to continue.
+ ...                                              
+l. ...}
+LaTeX does not know anything more about this error, sorry.
+Try typing <return> to proceed.
+If that doesn't work, type X <return> to quit.
+The sequence \l_tmpa_seq contains the items (without outer braces):
+>  {Hello,}
+>  {world,}
+>  {my}
+>  {name}
+>  {is}
+>  {LaTeX!}.
+============================================================

zutil/zutil.sty

@@ -4,9 +4,11 @@
 %%
 %% l3seq extras
 %%
-\msg_new:nnnn { zutil } { seq/empty-delimiter }
-  { Empty~delimiter~is~not~supported~in~#1. }
-  { I~will~skip~setting~#2. }
+\msg_new:nnn { zutil } { seq/empty-delimiter }
+  {
+    Empty~delimiter~is~not~supported~in~#1. \\
+    The~existing~definition~of~'#2'~will~not~be~altered.
+  }
 
 \cs_new_protected:Npn \zutil_seq_set_split_keep_braces:Nnn #1
   {
@@ -25,8 +27,8 @@
 % holds the user function, i.e. \zutil_seq_set_split_keep_braces:Nnn,
 % for use in error message.
 %
-% l3seq internals \__seq_set_split:Nw, \__seq_set_split_end:, and
-% \l__seq_internal_a_tl are used.
+% l3seq internals \__seq_set_split:Nw and \l__seq_internal_a_tl, along
+% with the undefined delimiter \__seq_set_split_end:, are used.
 \cs_new_protected:Npn \__zutil_seq_set_split:NNNNnn #1#2#3#4#5#6
   {
     \tl_if_empty:nTF {#5}