Improve test targets to use packr2 idiomatically

- not quite idiomatic because 'packr2 build' should preclude needing 'go build'
  - could not make that work
- added 'packr2 build' as file targets
- added documentation to help when working with packr
- made builds a little more efficient, see cf-platform-eng/marman#3

Co-authored-by: Pete Wall <[email protected]>
[#165363463]

Makefile

@@ -4,6 +4,7 @@ GO-VER = go1.12
 default: build
 
 # #### GO Binary Management ####
+
 deps-go-binary:
 	echo "Expect: $(GO-VER)" && \
 		echo "Actual: $$(go version)" && \
@@ -16,7 +17,9 @@ ifndef HAS_GO_IMPORTS
 	go get -u golang.org/x/tools/cmd/goimports
 endif
 
+
 # #### CLEAN ####
+
 clean-packr: deps-packr
 	packr2 clean
 
@@ -25,6 +28,7 @@ clean: deps-go-binary clean-packr
 	go clean --modcache
 
 # #### DEPS ####
+
 deps-modules: deps-goimports deps-go-binary
 	go mod download
 
@@ -34,43 +38,43 @@ deps-packr: deps-modules
 deps-counterfeiter: deps-modules
 	command -v counterfeiter >/dev/null 2>&1 || go get -u github.com/maxbrunsfeld/counterfeiter/v6
 
-
 deps: deps-modules deps-packr deps-counterfeiter
 
+
 # #### BUILD ####
-SRC = $(shell find . -name "*.go" | grep -v "_test\." )
 
+GENERATE_ARTIFACTS = generate/generate-packr.go packrd/packed-packr.go
+SRC = $(shell find . -name "*.go" | grep -v "_test\." )
 VERSION := $(or $(VERSION), "dev")
-
 LDFLAGS="-X github.com/cf-platform-eng/mrreport/version.Version=$(VERSION)"
 
-build/mrreport: $(SRC) deps
+$(GENERATE_ARTIFACTS): html/index.html
 	packr2 build
-	go build -o build/mrreport -ldflags ${LDFLAGS} ./cmd/mrreport/main.go
 
-build: build/mrreport
+build/mrreport: $(SRC) $(GENERATE_ARTIFACTS)
+	go build -o build/mrreport -ldflags ${LDFLAGS} ./cmd/mrreport/main.go
 
+build: deps build/mrreport
 
-build/mrreport-linux:
-	packr2 build
+build/mrreport-linux: $(SRC) $(GENERATE_ARTIFACTS)
 	GOARCH=amd64 GOOS=linux go build -o build/mrreport-linux -ldflags ${LDFLAGS} ./cmd/mrreport/main.go
 
-build-linux: build/mrreport-linux
+build-linux: deps build/mrreport-linux
 
-build/mrreport-darwin:
-	packr2 build
+build/mrreport-darwin: $(SRC) $(GENERATE_ARTIFACTS)
 	GOARCH=amd64 GOOS=darwin go build -o build/mrreport-darwin -ldflags ${LDFLAGS} ./cmd/mrreport/main.go
 
-build-darwin: build/mrreport-darwin
+build-darwin: deps build/mrreport-darwin
 
 build-all: build-linux build-darwin
 
 
 # #### TESTS ####
-units: deps
-	ginkgo -r -skipPackage features .
 
-features: deps
+units: deps # units test without packr content
+	ginkgo -r -tags=skippackr -skipPackage features .
+
+features: deps $(GENERATE_ARTIFACTS)
 	ginkgo -r -tags=feature features
 
 test: deps lint units features

README.md

@@ -15,3 +15,15 @@ mrreport takes log data from stdin, generates an HTML report, and outputs in on
 ```bash
 cat logfile.log | mrreport generate > report.html
 ```
+
+## Testing
+
+When you're testing, `packr` will use the generated content if it exists, not the content of `html/index.html`.
+
+* `make units` will avoid using packr
+* `make features` will regenerate using `packr2` and use the generated files
+
+When working with other test-runners (e.g. goland's), make sure you either
+  * run them with the `skippackr`
+  * add a before-run step that does `packr2 build`
+