Ensures kn cross platform build works in presubmit tests

 Fixes knative#364

 - Ensure kn cross platform build works in pre-submit tests
 - Run ./hack/build.sh -x after running existing pre-submit tests

go.mod

@@ -4,6 +4,7 @@ require (
 	github.com/golang/protobuf v1.3.2 // indirect
 	github.com/google/go-cmp v0.3.1 // indirect
 	github.com/google/go-containerregistry v0.0.0-20190723205234-74f764b9c575 // indirect
+	github.com/google/licenseclassifier v0.0.0-20190711054124-c3068f13fcc3 // indirect
 	github.com/hashicorp/golang-lru v0.5.3 // indirect
 	github.com/json-iterator/go v1.1.7 // indirect
 	github.com/knative/client v0.2.0 // indirect
@@ -12,8 +13,11 @@ require (
 	github.com/spf13/cobra v0.0.3
 	github.com/spf13/pflag v1.0.3
 	github.com/spf13/viper v1.3.1
+	github.com/stretchr/objx v0.2.0 // indirect
+	github.com/stretchr/testify v1.4.0 // indirect
 	golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2
 	golang.org/x/net v0.0.0-20190724013045-ca1201d0de80 // indirect
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gotest.tools v2.2.0+incompatible
 	k8s.io/api v0.0.0-20190226173710-145d52631d00
 	k8s.io/apimachinery v0.0.0-20190221084156-01f179d85dbc

go.sum

@@ -37,6 +37,7 @@ github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/btree v1.0.0 h1:0udJVsspx3VBr5FwtLhQQtuAsVc79tTq0ocGIPAU6qo=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
@@ -47,6 +48,8 @@ github.com/google/go-containerregistry v0.0.0-20190723205234-74f764b9c575/go.mod
 github.com/google/gofuzz v0.0.0-20161122191042-44d81051d367/go.mod h1:HP5RmnzzSNb993RKQDq4+1A4ia9nllfqcQFTQJedwGI=
 github.com/google/gofuzz v1.0.0 h1:A8PeW59pxE9IoFRqBp37U+mSNaQoZ46F1f0f863XSXw=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/licenseclassifier v0.0.0-20190711054124-c3068f13fcc3 h1:U7ujdmqSiFZHG6aamq/ARe14VLU86D7k2Zjcj5tCdVQ=
+github.com/google/licenseclassifier v0.0.0-20190711054124-c3068f13fcc3/go.mod h1:qsqn2hxC+vURpyBRygGUuinTO42MFRLcsmQ/P8v94+M=
 github.com/googleapis/gnostic v0.0.0-20170426233943-68f4ded48ba9/go.mod h1:sJBsCZ4ayReDTBIg8b9dl28c5xFWyhBTVRp3pOg5EKY=
 github.com/googleapis/gnostic v0.0.0-20170729233727-0c5108395e2d h1:7XGaL1e6bYS1yIonGp9761ExpPPV1ui0SAC59Yube9k=
 github.com/googleapis/gnostic v0.0.0-20170729233727-0c5108395e2d/go.mod h1:sJBsCZ4ayReDTBIg8b9dl28c5xFWyhBTVRp3pOg5EKY=
@@ -109,6 +112,8 @@ github.com/pmezard/go-difflib v0.0.0-20151028094244-d8ed2627bdf0/go.mod h1:iKH77
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday v1.5.2 h1:HyvC0ARfnZBqnXwABFeSZHpKvJHJJfPz81GNueLj0oo=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
+github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
+github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/spf13/afero v1.1.2 h1:m8/z1t7/fwjysjQRYbP0RD+bUIF/8tJwPdEZsI83ACI=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
 github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
@@ -123,9 +128,11 @@ github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnIn
 github.com/spf13/viper v1.3.1 h1:5+8j8FTpnFV4nEImW/ofkzEt8VoOiLXxdYIDsB73T38=
 github.com/spf13/viper v1.3.1/go.mod h1:ZiWeW+zYFKm7srdB9IoDzzZXaJaI5eL9QjNiN/DMA2s=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
 github.com/stretchr/testify v0.0.0-20151208002404-e3a8ff8ce365/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
@@ -155,6 +162,7 @@ golang.org/x/tools v0.0.0-20181011042414-1f849cf54d09/go.mod h1:n7NCudcB/nEzxVGm
 google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/inf.v0 v0.9.1 h1:73M5CoZyi3ZLMOyDlQh031Cx6N9NDJ2Vvfl76EDAgDc=
 gopkg.in/inf.v0 v0.9.1/go.mod h1:cWUDdTG/fYaXco+Dcufb5Vnc6Gp2YChqWtbxRZE0mXw=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

hack/build.sh

@@ -49,8 +49,13 @@ run() {
   fi
 
   if $(has_flag --build-cross -x); then
-    build_cross
-    exit 0
+    local failed=0
+    echo "🚧 Running kn cross platform build"
+    build_cross || failed=1
+    if (( failed )); then
+      echo "✋ Cross platform build failed"
+    fi
+    exit ${failed}
   fi
 
   if $(has_flag --watch -w); then
@@ -269,14 +274,17 @@ has_flag() {
 build_cross() {
   local ld_flags="$(build_flags $(dirname $0)/..)"
   local pkg="github.com/knative/client/pkg/kn/commands"
+  local failed=0
 
   export CGO_ENABLED=0
   echo "🚧 🐧 Building for Linux"
-  GOOS=linux GOARCH=amd64 go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-linux-amd64 ./cmd/... || exit 1
+  GOOS=linux GOARCH=amd64 go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-linux-amd64 ./cmd/... || failed=1
   echo "🚧 🍏 Building for macOS"
-  GOOS=darwin GOARCH=amd64 go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-darwin-amd64 ./cmd/... || exit 1
+  GOOS=darwin GOARCH=amd64 go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-darwin-amd64 ./cmd/... || failed=1
   echo "🚧 🎠 Building for Windows"
-  GOOS=windows GOARCH=amd64 go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-windows-amd64.exe ./cmd/... || exit
+  GOOS=windows GOARCH=amd64 go build -mod=vendor -ldflags "${ld_flags}" -o ./kn-windows-amd64.exe ./cmd/... || failed=1
+
+  return ${failed}
 }
 
 # Display a help message.

test/presubmit-tests.sh

@@ -35,6 +35,20 @@ export GO111MODULE=on
 export KNATIVE_VERSION=${KNATIVE_VERSION:-latest}
 source $(dirname $0)/../vendor/knative.dev/test-infra/scripts/presubmit-tests.sh
 
-# We use the default build, unit and integration test runners.
+# Run cross platform build to ensure kn compiles for Linux, macOS and Windows
+function run_cross_platform_build() {
+  local failed=0
+  header "Ensuring kn cross platform build"
+  ./hack/build.sh -x || failed=1
+  if (( failed )); then
+    results_banner "Cross platform build" ${failed}
+    exit ${failed}
+  fi
+}
+
 
+# We use the default build, unit and integration test runners.
 main $@
+
+# Run cross platform build tests after pre-submit build tests flow
+run_cross_platform_build