From 6fb4af06a18462c9bf7a40b2868eeb3a715024ef Mon Sep 17 00:00:00 2001
From: Ian Howell <ian.howell0@gmail.com>
Date: Wed, 16 Oct 2019 16:42:01 -0500
Subject: [PATCH] Fix the `make cover` target

This change has multiple benefits:

* Allows testing/coverage Makefile flags to be set from the command
  line. This allows a dev to easily test both correctness and coverage of
  a subset of packages by simply providing a value for the `PKG` make
  variable.

* Fixes an issue where an error message was being printed to stderr on
  each Zuul run, since the `COVER_PKG` variable required that Go is
  installed, and yet we don't install Go to the Zuul VM.

* Fixes an issue where Zuul VMs were crashing due to an Out Of Memory
  error. This was happening because of the way that the `coverpkg` flag
  works, which caused tests to occasionally require more than 8G of
  memory, exceeding the amount of memory on each Zuul VM.

* Cleans up the output when running `make cover`. Previously, the list
  of all packages was printed for coverage for each package, creating a
  lot of noise on the console.

However, it has the following negative:

* With the removal of the `coverpkg` flag, the `go test` command will no
  longer check coverage of packages which do not include any `_test.go`
  files. This puts the responsibility of assuring that coverage is
  correctly reflected onto the shoulders of developers and reviewers.

Change-Id: I7fef1dd26ef19b5f2ab4cf2d1be223bf82210492
---
 Makefile | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 6f3abb7b9..42c8a4736 100644
--- a/Makefile
+++ b/Makefile
@@ -21,12 +21,11 @@ DOCKER_IMAGE        ?= $(DOCKER_REGISTRY)/$(DOCKER_IMAGE_PREFIX)/$(DOCKER_IMAGE_
 DOCKER_TARGET_STAGE ?= release
 
 # go options
-PKG                 := ./...
-TESTS               := .
-TEST_FLAGS          :=
-COVER_FLAGS         :=
-COVER_PROFILE       := cover.out
-COVER_PKG           := $(shell go list ./... | tail -n+2 | grep -v "opendev.org/airship/airshipctl/testutil" | paste -sd"," -)
+PKG                 ?= ./...
+TESTS               ?= .
+TEST_FLAGS          ?=
+COVER_FLAGS         ?=
+COVER_PROFILE       ?= cover.out
 
 .PHONY: get-modules
 get-modules:
@@ -48,7 +47,7 @@ unit-tests:
 	@echo "All unit tests passed"
 
 .PHONY: cover
-cover: COVER_FLAGS = -covermode=atomic -coverprofile=$(COVER_PROFILE) -coverpkg=$(COVER_PKG)
+cover: COVER_FLAGS = -covermode=atomic -coverprofile=$(COVER_PROFILE)
 cover: unit-tests
 	@./tools/coverage_check $(COVER_PROFILE)