Add Docker setup for testing

Dockerfile

@@ -0,0 +1,22 @@
+FROM ubuntu
+
+RUN apt update && apt install -y \
+    git \
+    vim \
+    neovim
+
+WORKDIR root
+
+RUN git clone https://github.com/junegunn/vader.vim
+COPY . main
+
+RUN mkdir -p /root/.vim/pack/all/start
+RUN mkdir -p /root/.local/share/nvim/site/pack/all/start
+
+RUN ln -s /root/* /root/.vim/pack/all/start
+RUN ln -s /root/* /root/.local/share/nvim/site/pack/all/start
+
+RUN echo "set encoding=utf-8" > /root/.vim/vimrc
+
+WORKDIR main
+ENTRYPOINT ["./run-tests.sh"]

README.md

@@ -41,6 +41,9 @@ See [`:help secret-highlight`](./doc/secret.txt#L74) for more info.
 
 ## Testing
 
-`make` can be used to do testing in an isolated environment. The default target runs `test/*.vader` in Vim and Neovim.
+Docker can be used to run tests in an isolated environment:
 
-Thanks to [vim-sneak](https://github.com/justinmk/vim-sneak) for this idea.
+```
+$ docker build -t vim-secret .
+$ docker run --rm vim-secret [--verbose]
+```

makefile

@@ -1,20 +0,0 @@
-VIM = vim -N -u NORC -i NONE --cmd 'set rtp=test/vim-vader packpath='
-
-all: v nv
-
-v: test/vim-vader
-	$(VIM) -c 'Vader! test/*.vader'
-
-v-i: test/vim-vader
-	$(VIM) -c 'Vader test/*.vader'
-
-nv: test/vim-vader
-	n$(VIM) --headless -c 'Vader! test/*.vader'
-
-nv-i: test/vim-vader
-	n$(VIM) -c 'Vader test/*.vader'
-
-test/vim-vader:
-	git clone https://github.com/junegunn/vader.vim test/vim-vader || ( cd test/vim-vader && git pull --rebase )
-
-.PHONY: all v v-i nv nv-i

run-tests.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+if [[ $1 == "--verbose" || $1 == "-v" ]]; then
+    VERBOSE=1
+fi
+
+check_results() {
+    if [[ $? -eq 0 ]]; then
+        echo -e "\e[32m$1: PASS\e[0m"
+    else
+        echo -e "\e[31m$1: FAIL\e[0m"
+    fi
+
+    if [[ $VERBOSE == 1 ]]; then
+        sed -n '/^Starting Vader:/,$p' < vader_output
+    fi
+}
+
+export VADER_OUTPUT_FILE=vader_output
+
+vim.basic --not-a-term -c Vader! test/*.vader &>/dev/null
+check_results "VIM" $1
+rm vader_output
+
+if [[ $VERBOSE == 1 ]]; then
+    echo ""
+fi
+
+nvim -es -c Vader! test/*.vader
+check_results "NEOVIM" $1
+rm vader_output