setup docker to build for multiple swift versions locally

Makefile

@@ -1,4 +1,28 @@
 fmt:
 	swift-format format -i -r -p Sources Package.swift
 
-.PHONY: fmt
+test:
+	swift test
+
+test-linux-swift508:
+	docker compose run --rm --build swift508
+
+test-linux-swift509:
+	docker compose run --rm --build swift509
+
+test-linux-swift510:
+	docker compose run --rm --build swift510
+
+test-linux-swift600:
+	docker compose run --rm --build swift600
+
+test-linux-all:
+	docker compose run --rm --build
+
+.PHONY: fmt \
+	test \
+	test-linux-swift508 \
+	test-linux-swift509 \
+	test-linux-swift510 \
+	test-linux-swift600 \
+	test-linux-all

docker-compose.yml

@@ -0,0 +1,31 @@
+version: '3.7'
+
+name: linux-tests
+services:
+  swift508:
+    build:
+      context: .
+      dockerfile: swift508.Dockerfile
+    working_dir: /app
+    entrypoint: swift test
+
+  swift509:
+    build:
+      context: .
+      dockerfile: swift509.Dockerfile
+    working_dir: /app
+    entrypoint: swift test
+
+  swift510:
+    build:
+      context: .
+      dockerfile: swift510.Dockerfile
+    working_dir: /app
+    entrypoint: swift test
+
+  swift600:
+    build:
+      context: .
+      dockerfile: swift600.Dockerfile
+    working_dir: /app
+    entrypoint: swift test

swift508.Dockerfile

@@ -0,0 +1,13 @@
+FROM swift:5.8
+
+WORKDIR /app
+
+COPY Package.* ./
+
+RUN swift package resolve --skip-update \
+        $([ -f ./Package.resolved ] && echo "--force-resolved-versions" || true)
+
+COPY ./Plugins ./Plugins
+COPY ./Sources ./Sources
+COPY ./Tests ./Tests
+

swift509.Dockerfile

@@ -0,0 +1,13 @@
+FROM swift:5.9
+
+WORKDIR /app
+
+COPY Package.* ./
+
+RUN swift package resolve --skip-update \
+        $([ -f ./Package.resolved ] && echo "--force-resolved-versions" || true)
+
+COPY ./Plugins ./Plugins
+COPY ./Sources ./Sources
+COPY ./Tests ./Tests
+

swift510.Dockerfile

@@ -0,0 +1,13 @@
+FROM swift:5.10
+
+WORKDIR /app
+
+COPY Package.* ./
+
+RUN swift package resolve --skip-update \
+        $([ -f ./Package.resolved ] && echo "--force-resolved-versions" || true)
+
+COPY ./Plugins ./Plugins
+COPY ./Sources ./Sources
+COPY ./Tests ./Tests
+

swift600.Dockerfile

@@ -0,0 +1,13 @@
+FROM swift:6.0
+
+WORKDIR /app
+
+COPY Package.* ./
+
+RUN swift package resolve --skip-update \
+        $([ -f ./Package.resolved ] && echo "--force-resolved-versions" || true)
+
+COPY ./Plugins ./Plugins
+COPY ./Sources ./Sources
+COPY ./Tests ./Tests
+