feat(generate): parse CLI arguments to execution settings

Author: sis0k0

lib/commands/generate.ts

@@ -1,25 +1,87 @@
-import { run } from '@nativescript/schematics-engine';
+import { run, ExecutionOptions } from '@nativescript/schematics-engine';
 
 export class GenerateCommand implements ICommand {
 	public allowedParameters: ICommandParameter[] = [];
+	private executionOptions: ExecutionOptions;
 
-	constructor(private $logger: ILogger, private $errors: IErrors) {}
+	constructor(private $logger: ILogger,
+		private $options: IOptions,
+		private $errors: IErrors) { }
 
-	public async execute(args: string[]): Promise<void> {
+	public async execute(_rawArgs: string[]): Promise<void> {
 		try {
-			await run({
-				logger: this.$logger,
-				schematic: 'component',
-				schematicOptions: {
-					name: 'random',
-					// project: 'web-mobile-project'
-				},
-				directory: process.cwd(),
-			});
+			await run(this.executionOptions);
 		} catch (error) {
 			this.$errors.failWithoutHelp(error.message);
 		}
 	}
+
+	public async canExecute(rawArgs: string[]): Promise<boolean> {
+		this.setExecutionOptions(rawArgs);
+		this.validateExecutionOptions();
+
+		return true;
+	}
+
+	private validateExecutionOptions() {
+		if (!this.executionOptions.schematic) {
+			this.$errors.fail(`The generate command requires a schematic name to be specified.`);
+		}
+	}
+
+	private setExecutionOptions(rawArgs: string[]) {
+		const options = this.parseRawArgs(rawArgs);
+
+		this.executionOptions = {
+			...options,
+			logger: this.$logger,
+			directory: process.cwd(),
+		};
+	}
+
+	private parseRawArgs(rawArgs: string[]) {
+		const collection = this.$options.collection;
+		const schematic = rawArgs.shift();
+		const {
+			options: schematicOptions,
+			args: schematicArgs,
+		} = parseSchematicSettings(rawArgs);
+
+		return {
+			collection,
+			schematic,
+			schematicOptions,
+			schematicArgs,
+		};
+	}
+}
+
+/**
+ * Converts an array of command line arguments to options for the executed schematic.
+ * @param rawArgs The command line arguments. They should be in the format 'key=value' for strings or 'key' for booleans.
+ */
+function parseSchematicSettings(rawArgs: string[]) {
+	const [optionStrings, args] = partition<string>(rawArgs, item => item.includes('='));
+	const options = optionStrings
+		.map(o => o.split("=")) // split to key and value pairs
+		.map(([key, ...value]) => [key, value.join("=")]) // concat the value arrays if there are multiple = signs
+		.reduce((obj, [key, value]) => {
+			return { ...obj, [key]: value };
+		}, {});
+
+	return { options, args };
+}
+/**
+ * Splits an array into two groups based on a predicate.
+ * @param array The array to split.
+ * @param predicate The condition to be used for splitting.
+ */
+function partition<T>(array: T[], predicate: (item: T) => boolean): T[][] {
+	return array.reduce(([pass, fail], item) => {
+		return predicate(item) ?
+			[[...pass, item], fail] :
+			[pass, [...fail, item]];
+	}, [[], []]);
 }
 
 $injector.registerCommand("generate", GenerateCommand);