chore(validator): allow to not check jira reference

Author: sebastien-boulle

Diff for: README.md

@@ -197,6 +197,10 @@ Behind the hood, the script use `git log` to list all the commit thus any syntax
 You can also use the pre-push commit validator, simply copy, `pre-push`, `validator.sh` and `check.sh` files
 in `.git/hooks` directory of your repository.
 
+### OPTIONS
+
+- if `COMMIT_VALIDATOR_NO_JIRA` environment variable is set, no validation is done on JIRA refs.
+
 <!-- ROADMAP -->
 
 ## Roadmap
@@ -216,7 +220,7 @@ See the [open issues](https://github.com/lumapps/commit-msg-validator/issues) fo
 - [x] avoid trailing space
 - [x] allow automated revert commit
 - [ ] allow fixup! and squash! commit with an option
-- [ ] allow to not check JIRA reference with an option
+- [x] allow to not check JIRA reference with an option
 - [ ] enforce subject length (3 words at least)
 
 <!-- CONTRIBUTING -->

Diff for: validator.bats

@@ -460,6 +460,11 @@ LUM-2345'
   [[ `need_jira "fix"` -eq 1 ]]
 }
 
+@test "features and fixes commits don't need jira reference if set" {
+  [[ `COMMIT_VALIDATOR_NO_JIRA= need_jira "feat"` -eq 0 ]]
+  [[ `COMMIT_VALIDATOR_NO_JIRA= need_jira "fix"` -eq 0 ]]
+}
+
 @test "other commits don't need jira reference" {
   [[ `need_jira "docs"` -eq 0 ]]
   [[ `need_jira "test"` -eq 0 ]]

Diff for: validator.sh

@@ -208,16 +208,20 @@ validate_trailing_space() {
 need_jira() {
   local TYPE=$1
 
-  case $TYPE in
-    feat)
-      echo 1
-      ;;
-    fix)
-      echo 1
-      ;;
-    *)
-      echo 0
-  esac
+  if [[ -v COMMIT_VALIDATOR_NO_JIRA ]]; then
+    echo 0
+  else
+    case $TYPE in
+      feat)
+        echo 1
+        ;;
+      fix)
+        echo 1
+        ;;
+      *)
+        echo 0
+    esac
+  fi
 }
 
 validate_jira() {