From ac0c935b54d838861dae42cda844cc71410035f6 Mon Sep 17 00:00:00 2001
From: Dan Kortschak <dan@kortschak.io>
Date: Wed, 1 May 2019 03:02:31 +0930
Subject: [PATCH] travis: check for needed changes in go.mod and go.sum

---
 .travis.yml                        |  1 +
 .travis/script.d/check-generate.sh |  5 -----
 .travis/script.d/deps.sh           | 13 +++++++++++++
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index ae8fd527..0596658c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,6 +18,7 @@ os:
 env:
  global:
   - GO111MODULE=on
+  - GOFLAGS="-mod=readonly"
  matrix:
   - TAGS=""
   - TAGS="-tags bounds"
diff --git a/.travis/script.d/check-generate.sh b/.travis/script.d/check-generate.sh
index 1e1d1e5c..96a6d7bd 100755
--- a/.travis/script.d/check-generate.sh
+++ b/.travis/script.d/check-generate.sh
@@ -6,11 +6,6 @@ go generate gonum.org/v1/gonum/unit
 go generate gonum.org/v1/gonum/unit/constant
 go generate gonum.org/v1/gonum/graph/formats/dot
 
-# Discard changes to go.mod that have been made.
-# FIXME(kortschak): Sort out a policy of what we should do with go.mod changes.
-# If we want to check changes we should set `GOFLAGS=-mod=readonly` in .travis.yml.
-git checkout -- go.{mod,sum}
-
 if [ -n "$(git diff)" ]; then	
 	git diff
 	exit 1
diff --git a/.travis/script.d/deps.sh b/.travis/script.d/deps.sh
index d14b2071..4eafe9c7 100755
--- a/.travis/script.d/deps.sh
+++ b/.travis/script.d/deps.sh
@@ -2,6 +2,14 @@
 
 set -ex
 
+# Avoid contaminating the go.mod/go.sum files.
+WORK=$(mktemp -d)
+pushd $WORK
+
+# Work around go1.11 issue where go get will not work outside a module.
+# TODO(kortschak): Remove when go1.11 is no longer supported.
+go mod init fake || true
+
 # Required for format check.
 go get golang.org/x/tools/cmd/goimports
 # Required for imports check.
@@ -13,3 +21,8 @@ go get golang.org/x/tools/cmd/cover
 go get github.com/mattn/goveralls
 # Required for dot parser checks.
 ${TRAVIS_BUILD_DIR}/.travis/script.d/install-gocc.sh 66c61e91b3657c517a6f89d2837d370e61fb9430
+
+# Clean up.
+# TODO(kortschak): Remove when go1.11 is no longer supported.
+popd
+rm -rf $WORK