Replace swath of redundant tests with working arg-parse test.

arg-parsing-test.bats

@@ -0,0 +1,78 @@
+#!/usr/bin/env bats
+
+source lib/assert.bash
+source deploy.sh --source-only
+
+setup() {
+	run mktemp -dt deploy_test.XXXX
+	assert_success
+	tmp=$output
+	pushd "$tmp" >/dev/null
+}
+
+teardown() {
+	popd >/dev/null
+	rm -rf "$tmp"
+}
+
+set_env_vars() {
+	# Set environment variables.
+	export GIT_DEPLOY_USERNAME=env-username
+	export GIT_DEPLOY_EMAIL=env-email
+	export GIT_DEPLOY_APPEND_HASH=env-var
+}
+
+write_env_file() {
+	# Write a '.env' file to override environment variables.
+	cat <<-EOF > .env
+		GIT_DEPLOY_EMAIL=dotenv-email
+		GIT_DEPLOY_APPEND_HASH=env-file
+	EOF
+}
+
+write_conf_file() {
+	# Write a config-file to override '.env'.
+	cat <<-EOF > conf
+		GIT_DEPLOY_EMAIL=conf-email
+		GIT_DEPLOY_APPEND_HASH=conf-file
+	EOF
+}
+
+@test 'Arg-parsing defaults to in-script values.' {
+	parse_args
+	assert that "$append_hash" = "true"
+}
+
+@test '        overrides script defaults with environment variables.' {
+	set_env_vars
+
+	parse_args
+	assert that "$append_hash" = "env-var"
+}
+
+@test '        overrides environment variables with .env file.' {
+	set_env_vars
+	write_env_file
+
+	parse_args
+	assert that "$append_hash" = "env-file"
+}
+
+@test '        overrides .env with a file specified on the command-line.' {
+	set_env_vars
+	write_env_file
+	write_conf_file
+
+	parse_args --config-file conf
+	assert that "$append_hash" = "conf-file"
+}
+
+@test '        overrides everything with a command-line option.' {	
+	set_env_vars
+	write_env_file
+	write_conf_file
+
+	parse_args --config-file conf --no-hash
+	assert that "$append_hash" = "false"
+}
+