Add goimports as a check to the Github commit actions (#31432)

* Add goimports as a check to the Github commit actions

* check diff against main instead of last commit

* goimports should fix the problems

* fix up conditionals and wildcard matching

* specify origin/main in diff

* fetch main branch when checkout

* back to origin main

.github/workflows/checks.yml

@@ -141,6 +141,8 @@ jobs:
     steps:
       - name: "Fetch source code"
         uses: actions/checkout@v2
+        with:
+          fetch-depth: 0 # We need to do comparisons against the main branch.
 
       - name: Determine Go version
         id: go
@@ -178,9 +180,13 @@ jobs:
           restore-keys: |
             protobuf-tools-
 
+      - name: Install CI tooling
+        run: |
+          go install golang.org/x/tools/cmd/goimports@v0.1.11
+
       - name: "Code consistency checks"
         run: |
-          make fmtcheck generate staticcheck exhaustive protobuf
+          make fmtcheck importscheck generate staticcheck exhaustive protobuf
           if [[ -n "$(git status --porcelain)" ]]; then
             echo >&2 "ERROR: Generated files are inconsistent. Run 'make generate' and 'make protobuf' locally and then commit the updated files."
             git >&2 status --porcelain

Makefile

@@ -35,6 +35,9 @@ protobuf:
 fmtcheck:
 	@sh -c "'$(CURDIR)/scripts/gofmtcheck.sh'"
 
+importscheck:
+	@sh -c "'$(CURDIR)/scripts/goimportscheck.sh'"
+
 staticcheck:
 	@sh -c "'$(CURDIR)/scripts/staticcheck.sh'"
 
@@ -63,4 +66,4 @@ website/build-local:
 # under parallel conditions.
 .NOTPARALLEL:
 
-.PHONY: fmtcheck generate protobuf website website-test staticcheck website/local website/build-local
+.PHONY: fmtcheck importscheck generate protobuf website website-test staticcheck website/local website/build-local

scripts/goimportscheck.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+# Check goimports
+echo "==> Checking the code complies with goimports requirements..."
+target_files=$(git diff --name-only origin/main | grep "\.go")
+
+if [[ -z ${target_files}  ]]; then
+  exit 0
+fi
+
+goimports_files=$(goimports -w -l -local github.com/hashicorp/terraform/ ${target_files})
+if [[ -n ${goimports_files} ]]; then
+  echo 'goimports needs running on the following files:'
+  echo "${goimports_files}"
+  echo "You can use the command and flags \`goimports -w -l -local github.com/hashicorp/terraform/\` to reformat the code"
+  exit 1
+fi
+
+exit 0