Add is_key_in assertion method

README.md

@@ -137,6 +137,19 @@ Asserts that a value is not included in the comparison array.
 assert 'a' not_in 'x' 'y' 'z'
 ```
 
+#### is_key_in
+
+Asserts that a value is a key in a hash.
+
+```sh
+typeset -A hash; hash=(
+  'a' 1
+  'b' 2
+  'c' 3
+)
+assert 'a' is_key_in ${(@kv)hash}
+```
+
 #### exists
 
 Asserts that the given path exists

zunit

@@ -147,6 +147,24 @@ function _zunit_assert_not_in() {
   exit 1
 }
 
+###
+# Assert that a value is a key in a hash
+###
+function _zunit_assert_is_key_in() {
+  local i found=0 value=$1
+  local -A hash
+  hash=(${(@)@:2})
+
+  for k v in ${(@kv)hash}; do
+    [[ $k = $value ]] && found=1
+  done
+
+  [[ $found -eq 1 ]] && return 0
+
+  echo "'$value' is not a key in (${(@kv)hash})"
+  exit 1
+}
+
 ###
 # Assert the a path exists
 ###