feat(index.js): add option to have maximum line length in commit message

Author: maxorlovsky

index.js

@@ -18,7 +18,8 @@ class gitCommitMsg {
                 'perf',
                 'test',
                 'revert'
-            ]
+            ],
+            lineLength: 72
         }
 
         this.init();
@@ -27,14 +28,7 @@ class gitCommitMsg {
     init() {
         // Check if config exists and if we need to use the default one
         if (this.package['git-commit-hook']) {
-            const config = this.package['git-commit-hook'];
-
-            if (config.types && !Array.isArray(config.types)) {
-                console.error('git-commit-hook: config.types is suppose to be array');
-                process.exit(1);
-            } else if (config.types) {
-                this.config.types = config.types;
-            }
+            this.populateConfig();
         }
 
         // Breaking the message by line
@@ -44,17 +38,63 @@ class gitCommitMsg {
         if (!this.checkTypeSubject()) {
             this.stop();
         }
+
+        // Check if lines length is fine, check only if lineLength is integer and not boolean false
+        if (this.config.lineLength !== 0 && !this.checkLength()) {
+            this.stop();
+        }
+
         console.log('error');
         this.stop();
 
         process.exit(0);
     }
 
+    // Replace default config with config from package.json
+    populateConfig() {
+        const config = this.package['git-commit-hook'];
+
+        // In case there is config.types available in package.json, check if it's array and if set, if set, replace default one
+        if (config.types && !Array.isArray(config.types)) {
+            console.error('git-commit-hook: config.types is suppose to be array');
+            this.stop();
+        } else if (config.types) {
+            this.config.types = config.types;
+        }
+
+        // In case there is config.lineLength available in package.json, check if it's number and if set, if set, replace default one
+        if (config.lineLength && typeof config.lineLength !== 'number') {
+            console.error('git-commit-hook: config.lineLength is suppose to be number, remove the rule or set to 0 if you don\'t want to force it');
+            this.stop();
+        } else if (config.lineLength) {
+            this.config.lineLength = config.lineLength;
+        }
+    }
+
+    // Check length of every line of commit message and validate that there are no long lines in it
+    checkLength() {
+        // Start line with number one, to make it less confusing
+        let line = 1;
+
+        for (const message of this.message) {
+            // If line is longer than allowed, show error message and exit the process
+            if (message.length > this.config.lineLength) {
+                console.error(`git-commit-hook: Commit message in line ${line} have more characters than allowed in a single line, please break it down, maximum is ${this.config.lineLength}`);
+                return false;
+            }
+
+            line++;
+        }
+    }
+
+    // Check first line of commit message, if there is [Type]([optional scope]): [Subject]
+    // Semicolon with space is always mandatory after the Type
     checkTypeSubject() {
         const types = this.config.types.join('|');
         let regStr = `(${types})(\(.*\))?\\:`;
         const regExpType = new RegExp(regStr);
 
+        // Check type and semicolon
         if (this.message[0].search(regExpType) === -1) {
             console.error(`git-commit-hook: Type should follow the rules "${types}(scope/filename): Subject"`);
             return false;
@@ -63,6 +103,7 @@ class gitCommitMsg {
         regStr += ' .*';
         const regExpSubject = new RegExp(regStr);
 
+        // Check if there is subject after semicolon
         if (this.message[0].search(regExpSubject) === -1) {
             console.error('git-commit-hook: Subject is not set or there is no space after semicolon');
             return false;
@@ -71,6 +112,7 @@ class gitCommitMsg {
         return true;
     }
 
+    // Killing the process
     stop() {
         process.exit(1);
     }