Refactor the unit test run script to be more idiomatic shell

test/run

@@ -2,22 +2,28 @@
 
 # Main ├────────────────────────────────────────────────────────────────────────
 
-main() { number_tests=0 number_failures=0
-  dirs=$@
-  test=$(pwd)
-  work=$(mktemp --directory)
+main() {
+  local number_tests=0
+  local number_failures=0
+  local dirs=$@
+  local test=$(pwd)
+  local work=$(mktemp --directory)
   cp --recursive . $work
   trap "rm --recursive $work" EXIT
   for dir in $(find $dirs -type d); do
-    cd $test/$dir; test_files=$(find * -name out -o -name selections -o -name state)
-    cd $work/$dir; { IFS=¬
-      indent=$(repeat ' ' $(pwd | sed "s|$test||" | tr --delete --complement / | awk '{ print length }'))
-      name=$(basename $PWD)
-      ! exists cmd && {
+    cd $test/$dir;
+    local test_files=$(find * -name out -o -name selections -o -name state)
+    cd $work/$dir;
+    IFS=¬
+    local indent=$(repeat ' ' $(pwd | sed "s|$test||" | tr --delete --complement / | awk '{ print length }'))
+    local name=$(basename $PWD)
+    if ! exists cmd; then
       echo "$indent$name"
-      } || { nop=$((number_tests++))
+    else
+      ((number_tests++))
       touch in; cp in out
-        kak_commands="set global autoreload yes
+      local kak_commands="
+        set global autoreload yes
         try %{
         source rc
         }
@@ -39,28 +45,32 @@ main() { number_tests=0 number_failures=0
       kak out -n -e $kak_commands
       IFS=$'\n'
       for expect in $test_files; do
-          cmp --quiet $test/$dir/$expect $expect && {
+        if cmp --quiet $test/$dir/$expect $expect; then
           echo "$indent$name" | colorize green normal
-          } || { nop=$((number_failures++))
+        else
+          ((number_failures++))
           echo "$indent$name" | colorize red normal
           echo
           IFS=$'\n'
-            for line in $(diff --unified $test/$dir/$expect $expect); do IFS=¬
-              first_character=$(head --bytes 1 <<< $line)
-              color=$(match $first_character + green - red @ magenta none)
-              colorize $color normal <<< $line
+          for line in $(diff --unified $test/$dir/$expect $expect); do
+            IFS=¬
+            local first_character=$(echo "$line" | head --bytes 1)
+            local color=$(match $first_character + green - red @ magenta none)
+            echo "$line" | colorize $color normal
           done
           echo
-            colorize yellow normal <<< "debug buffer:"
+          echo "debug buffer:" | colorize yellow normal
           cat debug
           echo
-          }
+        fi
       done
-      }
-    }
+    fi
   done
-  (( $number_failures > 0 )) && color=red ||
+  if (( $number_failures > 0 )); then
+    color=red
+  else
     color=green
+  fi
   echo
   echo Resume:
   echo $number_tests tests, $number_failures failures | colorize $color normal
@@ -69,22 +79,29 @@ main() { number_tests=0 number_failures=0
 # Utility ├─────────────────────────────────────────────────────────────────────
 
 match() {
-  expression=$1; shift
-  while [[ $@ ]]; do
-    pattern=$1; shift; value=$1 next=$1 default_value=$pattern
-    [[ $next ]] || {
+  expression="$1";
+  shift
+  while [[ "$@" ]]; do
+    local pattern="$1"
+    shift
+    local value="$1"
+    local next="$1"
+    local default_value="$pattern"
+    if [[ -z "$next" ]]; then
       echo $default_value
       return 1
-    }
-    [[ $expression = $pattern ]] && {
-      echo $value
+    fi
+    if [[ "$expression" = "$pattern" ]]; then
+      echo "$value"
       return 0
-    }
+    fi
     shift
   done
 }
 
-repeat() { text=$1 count=${2:-0}
+repeat() {
+  local text=$1
+  local count=${2:-0}
   echo $(yes $text | head --lines $count | join)
 }
 
@@ -96,20 +113,25 @@ exists() {
   test -e $@
 }
 
-get_ansi_code() { color_name=${1:-none} style_name=${2:-none}
-  color='none    00
+get_ansi_code() {
+  local color_name=${1:-none}
+  local style_name=${2:-none}
+  local color='none    00
                red     31
                green   32
                yellow  33
                magenta 35'
-  style='none    00
+  local style='none    00
                bold    01'
-  color_nr=$(awk "/$color_name/ { print \$2 }" <<< "$color")
-  style_nr=$(awk "/$style_name/ { print \$2 }" <<< "$style")
-  sed s/COLOR_NR/$color_nr/';'s/STYLE_NR/$style_nr/ <<< '\e[STYLE_NR;COLOR_NRm'
+  local color_nr=$(echo "$color" | awk "/$color_name/ { print \$2 }")
+  local style_nr=$(echo "$style" | awk "/$style_name/ { print \$2 }")
+  echo '\e[STYLE_NR;COLOR_NRm' | sed s/COLOR_NR/$color_nr/';'s/STYLE_NR/$style_nr/
 }
 
-colorize() { text=$(cat) color_name=${1:-none} style_name=${2:-none}
+colorize() {
+  local text=$(cat)
+  local color_name=${1:-none}
+  local style_name=${2:-none}
   echo -e "$(get_ansi_code $color_name $style_name)$text$(get_ansi_code none none)"
 }