feat: 🎸 add IconNameSubset helper type

This helper type can be used to generate types for your icons. `type
emojiIcons = IconNameSubset<[typeof myIconSmile, typeof myIconLaugh]>;`

src/lib/converters/constants.converter.ts

@@ -1,7 +1,8 @@
 import {
   generateInterfaceDefinition,
   generateSvgConstant,
-  generateTypeDefinition
+  generateTypeDefinition,
+  generateTypeHelper
 } from '../generators/code-snippet-generators';
 import { writeFile } from '../helpers/file-helpers';
 import { error, success, underlineSuccess } from '../helpers/log-helper';
@@ -17,14 +18,15 @@ const getSvgConstants = svgDefinitions => {
 };
 
 export const convertToConstants = async (conversionOptions: ConstantsConversionOptions): Promise<void> => {
-  const { outputDirectory, fileName } = conversionOptions;
+  const { outputDirectory, fileName, interfaceName } = conversionOptions;
   try {
     const svgDefinitions = await filesProcessor(conversionOptions);
     if (svgDefinitions.length) {
       const svgContants = getSvgConstants(svgDefinitions);
       const typeDefinition = generateTypeDefinition(conversionOptions, svgDefinitions);
       const interfaceDefinition = generateInterfaceDefinition(conversionOptions);
-      const fileContent = `${svgContants}${typeDefinition}${interfaceDefinition}`;
+      const typeHelper = generateTypeHelper(interfaceName);
+      const fileContent = `${svgContants}${typeDefinition}${interfaceDefinition}${typeHelper}`;
       await writeFile(outputDirectory, fileName, fileContent);
       success(`Icons file successfully generated under ${underlineSuccess(outputDirectory)}`);
     }

src/lib/converters/files.converter.ts

@@ -3,7 +3,8 @@ import {
   generateExportStatement,
   generateInterfaceDefinition,
   generateSvgConstant,
-  generateTypeDefinition
+  generateTypeDefinition,
+  generateTypeHelperWithImport
 } from '../generators/code-snippet-generators';
 import { generateCompleteIconSetContent } from '../helpers/complete-icon-set.helper';
 import { deleteFiles, deleteFolder, writeFile } from '../helpers/file-helpers';
@@ -19,6 +20,7 @@ export const convertToFiles = async (conversionOptions: FileConversionOptions):
     modelFileName,
     additionalModelOutputPath,
     iconsFolderName,
+    interfaceName,
     compileSources,
     exportCompleteIconSet,
     barrelFileName
@@ -49,10 +51,10 @@ export const convertToFiles = async (conversionOptions: FileConversionOptions):
       generatedFileNames.push(completeIconSetFileName);
     }
 
-    let indexFileContent = generatedFileNames
+    let indexFileContent = generateTypeHelperWithImport(interfaceName, iconsFolderName, modelFileName);
+    indexFileContent += generatedFileNames
       .map((generatedFileName: string) => generateExportStatement(generatedFileName, iconsFolderName))
       .join('');
-
     separatorEnd();
 
     indexFileContent += generateExportStatement(modelFileName, iconsFolderName);

src/lib/generators/code-snippet-generators.spec.ts

@@ -1,4 +1,5 @@
 import { SvgDefinition } from '../converters/shared.converter';
+import { unformatedString } from '../helpers/test-helpers';
 import { ConstantsConversionOptions } from '../options/conversion-options';
 
 import {
@@ -7,6 +8,8 @@ import {
   generateNamedImportStatement,
   generateSvgConstant,
   generateTypeDefinition,
+  generateTypeHelper,
+  generateTypeHelperWithImport,
   generateTypeName,
   generateVariableName
 } from './code-snippet-generators';
@@ -148,4 +151,30 @@ describe('Generators', () => {
       expect(generatedNamedImpoort).toEqual(expectedNamedImport);
     });
   });
+
+  describe('Type helper', () => {
+    it('should generate the correct type helper statement', () => {
+      const interfaceName = 'MyIcons';
+      const expectedStatement = `
+        export type IconNameSubset<T extends Readonly<${interfaceName}[]>> = T[number]['name'];
+       `;
+
+      const generatedStatement = generateTypeHelper(interfaceName);
+      expect(unformatedString(generatedStatement)).toEqual(unformatedString(expectedStatement));
+    });
+
+    it('should generate the correct type helper and import statement', () => {
+      const interfaceName = 'MyIcon';
+      const modelFileName = 'my-icons';
+      const iconsFolderName = 'build';
+
+      const expectedStatement = `
+        import {${interfaceName}} from './${iconsFolderName}/${modelFileName}';
+        export type IconNameSubset<T extends Readonly<${interfaceName}[]>> = T[number]['name'];
+       `;
+
+      const generatedStatement = generateTypeHelperWithImport(interfaceName, iconsFolderName, modelFileName);
+      expect(unformatedString(generatedStatement)).toEqual(unformatedString(expectedStatement));
+    });
+  });
 });

src/lib/generators/code-snippet-generators.ts

@@ -88,6 +88,19 @@ export const generateVariableName = (prefix: string, filenameWithoutEnding): str
   return prefix ? `${prefix}${capitalize(camelCased)}` : camelCased;
 };
 
+export const generateTypeHelper = (interfaceName: string): string => `
+    export type IconNameSubset<T extends Readonly<${interfaceName}[]>> = T[number]['name'];
+    `;
+
+export const generateTypeHelperWithImport = (
+  interfaceName: string,
+  iconsFolderName: string,
+  modelFileName: string
+): string => `
+    import {${interfaceName}} from './${iconsFolderName}/${modelFileName}';
+    ${generateTypeHelper(interfaceName)}
+    `;
+
 const capitalize = (value: string): string => {
   return value.charAt(0).toUpperCase() + value.slice(1);
 };