diff --git a/highlighters/main/test-data/dollar-quoted.zsh b/highlighters/main/test-data/dollar-quoted.zsh
index 31f8f5a..b90d709 100644
--- a/highlighters/main/test-data/dollar-quoted.zsh
+++ b/highlighters/main/test-data/dollar-quoted.zsh
@@ -29,8 +29,9 @@
 # -------------------------------------------------------------------------------------------------
 
 ZSH_HIGHLIGHT_STYLES[dollar-quoted-argument]=$unused_highlight
-BUFFER=": \$'*'"
+BUFFER=": \$'*' 'foo'"
 
 expected_region_highlight=(
   "3 6 $ZSH_HIGHLIGHT_STYLES[dollar-quoted-argument]" # $'*' - not a glob
+  "8 12 $ZSH_HIGHLIGHT_STYLES[single-quoted-argument]" # 'foo'
 )
diff --git a/highlighters/main/test-data/double-hyphen-option.zsh b/highlighters/main/test-data/double-hyphen-option.zsh
new file mode 100644
index 0000000..8fad394
--- /dev/null
+++ b/highlighters/main/test-data/double-hyphen-option.zsh
@@ -0,0 +1,36 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2010-2011 zsh-syntax-highlighting contributors
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are permitted
+# provided that the following conditions are met:
+#
+#  * Redistributions of source code must retain the above copyright notice, this list of conditions
+#    and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright notice, this list of
+#    conditions and the following disclaimer in the documentation and/or other materials provided
+#    with the distribution.
+#  * Neither the name of the zsh-syntax-highlighting contributors nor the names of its contributors
+#    may be used to endorse or promote products derived from this software without specific prior
+#    written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# -------------------------------------------------------------------------------------------------
+# -*- mode: zsh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
+# vim: ft=zsh sw=2 ts=2 et
+# -------------------------------------------------------------------------------------------------
+
+ZSH_HIGHLIGHT_STYLES[double-hyphen-option]=$unused_highlight
+BUFFER='hello --world'
+
+expected_region_highlight=(
+  "7 13 $ZSH_HIGHLIGHT_STYLES[double-hyphen-option]" # --world
+)
diff --git a/highlighters/main/test-data/function.zsh b/highlighters/main/test-data/function.zsh
new file mode 100644
index 0000000..ecf5572
--- /dev/null
+++ b/highlighters/main/test-data/function.zsh
@@ -0,0 +1,48 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2010-2011 zsh-syntax-highlighting contributors
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are permitted
+# provided that the following conditions are met:
+#
+#  * Redistributions of source code must retain the above copyright notice, this list of conditions
+#    and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright notice, this list of
+#    conditions and the following disclaimer in the documentation and/or other materials provided
+#    with the distribution.
+#  * Neither the name of the zsh-syntax-highlighting contributors nor the names of its contributors
+#    may be used to endorse or promote products derived from this software without specific prior
+#    written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# -------------------------------------------------------------------------------------------------
+# -*- mode: zsh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
+# vim: ft=zsh sw=2 ts=2 et
+# -------------------------------------------------------------------------------------------------
+
+ZSH_HIGHLIGHT_STYLES[function]=$unused_highlight
+cd() {
+  builtin cd "$@"
+}
+ls() {
+  command ls "$@"
+}
+BUFFER='cd;ls'
+
+# Use $unused_highlight to see that function highlighting has precedence over command and builtin
+
+expected_region_highlight=(
+  "1 2 $ZSH_HIGHLIGHT_STYLES[function]" # cd
+  "4 5 $ZSH_HIGHLIGHT_STYLES[function]" # ls
+)
+
+# don't 'unfunction cd ls', since cd() and ls() should still be a functions
+# when _zsh_highlight runs.  Leaving the wrapper functions is harmless.