A rule that rejects obvious words in the commit title

commitlint.config.ts

@@ -1,3 +1,5 @@
+import {obviousWords} from './obviouswords'
+
 // to convert from 'any' type
 function convertAnyToString(potentialString: any, paramName: string): string {
     if (potentialString === null || potentialString === undefined) {
@@ -36,6 +38,7 @@ module.exports = {
         'trailing-whitespace': [RuleStatus.Error, 'always'],
         'prefer-slash-over-backslash': [RuleStatus.Error, 'always'],
         'type-space-before-paren': [RuleStatus.Error, 'always'],
+        'reject-obvious-words': [RuleStatus.Error, 'always'],
     },
     plugins: [
         // TODO (ideas for more rules):
@@ -81,6 +84,22 @@ module.exports = {
                     ];
                 },
 
+                'reject-obvious-words': ({header}: {header:any}) => {
+                    let headerStr = convertAnyToString(header, "header");
+                    let offence = false;
+
+                    let colonFirstIndex = headerStr.indexOf(":");
+                    let titleStartIndex = Math.max(0, colonFirstIndex + 1);
+                    let title = headerStr.substring(titleStartIndex, headerStr.length).trim();
+                    let firstWordInTitle = title.split(' ')[0];
+                    offence = obviousWords.includes(firstWordInTitle);  
+
+                    return [
+                        !offence,
+                        `Please don't use obvious words such as ${firstWordInTitle} in the commit title`
+                    ];
+                },
+
                 'type-space-after-colon': ({header}: {header:any}) => {
                     let headerStr = convertAnyToString(header, "header");
 

commitlintplugins.test.ts

@@ -87,6 +87,30 @@ test('prefer-slash-over-backslash2', () => {
 });
 
 
+test('reject-obvious-words1', () => {
+    let commitMsgWithObviousWordAfterColon = "foo: modify bla bla";
+    let rejectObviousWord1 = runCommitLintOnMsg(commitMsgWithObviousWordAfterColon);
+    // console.log('==========>' + rejectObviousWord1.stdout)
+    expect(rejectObviousWord1.status).not.toBe(0);
+});
+
+
+test('reject-obvious-words2', () => {
+    let commitMsgWithObviousWordAfterColon = "foo: change bla bla";
+    let rejectObviousWord2 = runCommitLintOnMsg(commitMsgWithObviousWordAfterColon);
+    // console.log('==========>' + rejectObviousWord2.stdout)
+    expect(rejectObviousWord2.status).not.toBe(0);
+});
+
+
+test('reject-obvious-words3', () => {
+    let commitMsgWithoutObviousWordAfterColon = "foo: bla bla bla";
+    let rejectObviousWord3 = runCommitLintOnMsg(commitMsgWithoutObviousWordAfterColon);
+    // console.log('==========>' + rejectObviousWord3.stdout)
+    expect(rejectObviousWord3.status).toBe(0);
+});
+
+
 test('subject-lowercase1', () => {
     let commitMsgWithUppercaseAfterColon = "foo: Bar baz";
     let subjectLowerCase1 = runCommitLintOnMsg(commitMsgWithUppercaseAfterColon);

obviouswords.ts

@@ -0,0 +1,5 @@
+export let obviousWords = [
+    "change",
+    "update",
+    "modify"
+]