test: Add Docker container for testing [skip ci]

.dockerignore

@@ -0,0 +1,7 @@
+.*
+
+!.eslintrc.json
+!.prettierrc.json
+
+coverage
+node_modules

Makefile

@@ -0,0 +1,22 @@
+cmd := "bash"
+msg := ""
+IMAGE_NAME := actions-hugo-dev:latest
+DOCKER_BUILD := docker build . -t $(IMAGE_NAME) --file ./__tests__/Dockerfile
+DOCKER_RUN := docker run --rm -i -t -v ${PWD}:/repo -v ~/.gitconfig:/etc/gitconfig $(IMAGE_NAME)
+
+
+.PHONY: build
+build:
+	$(DOCKER_BUILD)
+
+.PHONY: run
+run:
+	$(DOCKER_RUN) $(cmd)
+
+.PHONY: test
+test:
+	$(DOCKER_RUN) npm test
+
+.PHONY: commit
+commit:
+	$(DOCKER_RUN) git commit -m "$(msg)"

__tests__/Dockerfile

@@ -0,0 +1,11 @@
+FROM node:12-slim
+
+WORKDIR /repo
+
+RUN apt-get update && \
+    apt-get -y install --no-install-recommends \
+    git \
+    bash && \
+    rm -rf /var/lib/apt/lists/*
+
+CMD [ "bash" ]