From 2f2334a3f33221979ec63e88095d65dd0c9eee9e Mon Sep 17 00:00:00 2001
From: Chris Goller <goller@gmail.com>
Date: Mon, 8 Oct 2018 13:16:06 -0500
Subject: [PATCH] ci(gofmt): check go formatting with each PR

---
 .circleci/config.yml |  1 +
 Makefile             |  5 ++++-
 etc/checkfmt.sh      | 29 +++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100755 etc/checkfmt.sh

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 0a5a439182..f9613830c6 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -43,6 +43,7 @@ jobs:
             - platform-gocache-                              # Matches a new branch.
       - run: make test-go # This uses the test cache so it may succeed or fail quickly.
       - run: make vet
+      - run: make checkfmt
       - run: make test-go-race # This doesn't use the test cache, and will not complete quickly.
       # TODO add these checks to the Makefile
       # - run: go get -v -t -d ./...
diff --git a/Makefile b/Makefile
index 23f4a935d0..050fc63654 100644
--- a/Makefile
+++ b/Makefile
@@ -105,7 +105,10 @@ chronograf/ui/build:
 #
 
 fmt: $(SOURCES_NO_VENDOR)
-	goimports -w $^
+	gofmt -w -s $^
+
+checkfmt: $(SOURCES_NO_VENDOR)
+	./etc/checkfmt.sh
 
 chronograf/dist/dist_gen.go: chronograf/ui/build $(UISOURCES)
 	 $(GO_GENERATE) ./chronograf/dist/...
diff --git a/etc/checkfmt.sh b/etc/checkfmt.sh
new file mode 100755
index 0000000000..dc2ad9ca65
--- /dev/null
+++ b/etc/checkfmt.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+
+HAS_FMT_ERR=0
+# For every Go file in the project, excluding vendor...
+for file in $(go list -f '{{$dir := .Dir}}{{range .GoFiles}}{{printf "%s/%s\n" $dir .}}{{end}}' ./...); do
+  # ... if file does not contain standard generated code comment (https://golang.org/s/generatedcode)...
+  if ! grep -Exq '^// Code generated .* DO NOT EDIT\.$' $file; then
+    FMT_OUT="$(gofmt -l -d -e $file)" # gofmt exits 0 regardless of whether it's formatted.
+    # ... and if gofmt had any output...
+    if [[ -n "$FMT_OUT" ]]; then
+      if [ "$HAS_FMT_ERR" -eq "0" ]; then
+        # Only print this once.
+        HAS_FMT_ERR=1
+        echo 'Commit includes files that are not gofmt-ed' && \
+        echo 'run "make fmt"' && \
+        echo ''
+      fi
+      echo "$FMT_OUT" # Print output and continue, so developers don't fix one file at a t
+    fi
+   fi
+done
+
+## print at the end too... sometimes it is nice to see what to do at the end.
+if [ "$HAS_FMT_ERR" -eq "1" ]; then
+    echo 'Commit includes files that are not gofmt-ed' && \
+    echo 'run "make fmt"' && \
+    echo ''
+fi
+exit "$HAS_FMT_ERR"