Adding support for config JSON file to index.js

bin/index.js

@@ -13,34 +13,54 @@ const dist = path.join(process.cwd(), "dist");
 let outputPath = dist;
 
 //stylesheet url
-let stylesheetUrl = "";
+let stylesheetUrl = undefined;
 
 const program = new Command();
 program
     .version(`Name: ${pkjson.name} \nVersion: ${pkjson.version}`, '-v, --version', 'Output the current version')
-    .requiredOption('-i, --input <file or directory', 'Designate an input file or directory')
+    .option('-i, --input <file or directory>', 'Designate an input file or directory')
     .option('-o, --output <directory>', 'Designate an ouput directory', dist)
     .option('-s, --stylesheet <stylesheet url>', 'Link to a stylesheet url', '')
+    .option('-c, --config <config json file>', 'Link to file that specifies all SSG options')
     .showHelpAfterError();
 program.parse(process.argv);
 
 const options = program.opts();
+//Config file option
+if(options.config !== undefined) {
+    try {
+        let configData = fs.readFileSync(options.config);
+        let configOptions = JSON.parse(configData); 
+        for(const [key, value] of Object.entries(configOptions)) {
+            value || value.length > 0 ? options[`${key}`] = `${value}` : options[`${key}`] = undefined;
+        }
+        if(!options.input) {
+            console.log(`error: input <file or directory> is not specified in config file ${options.config}`);
+            process.exit(-1);
+        }
+    } catch(error) {
+        console.error(`Can't read or parse config file ${options.config}\n ${error}`);
+    }
+}
 //Output option
 if(options.output !== dist){
     if(fs.existsSync(options.output)){
         outputPath = options.output;
     }
     else{
-        console.log(`Output directory "${options.output}" doesn't exist, outputting all files to ./dist`);
+        console.log(`Output directory ${options.output} doesn't exist, outputting all files to ./dist`);
     }
 }
 //Stylesheet option
-if(options.stylesheet !== '')
+if(options.stylesheet !== undefined)
     stylesheetUrl = options.stylesheet;
 //Input option
 if(options.input !== undefined)
     processInput(options.input);
-
+else {
+    console.error("error: required option input <file or directory> is not specified");
+    process.exit(-1);
+}
 /*
   Function processes the input option