Add prefix config

README.md

@@ -88,6 +88,7 @@ import { configure, DefaultBEMDelimiters } from 'bem-composer';
 
 // Configure BEM constructor with custom delimiters.
 const cbem = configure({
+  prefix: 'bem-',
   element: '__',
   modifier: '~~',
   modifierValue: '~'
@@ -98,7 +99,7 @@ console.log(
     name: 'active',
     value: 'hover'
   }).toString()
-); // block__icon~~active~hover
+); // bem-block__icon~~active~hover
 ```
 
 ## Curried API

src/bem.test.ts

@@ -259,6 +259,7 @@ describe('curried api', () => {
 
 describe('custom delimiters', () => {
   const cbem = configure({
+    prefix: 'bem-',
     element: '__',
     modifier: '~~',
     modifierValue: '~'
@@ -271,6 +272,7 @@ describe('custom delimiters', () => {
       }).toString()
     ).toBe(
       [
+        'bem-',
         BlockName,
         '__',
         ElementName,

src/bem.ts

@@ -8,6 +8,7 @@ import {
 import { block } from './block';
 
 export const DefaultBEMDelimiters: BEMDelimiters = {
+  prefix: '',
   element: '--',
   modifier: '__',
   modifierValue: '-'

src/block.ts

@@ -30,7 +30,7 @@ export function block(name: string, delimiters: BEMDelimiters): BEMBlock {
   }
 
   const toString = (): string => {
-    return name;
+    return delimiters.prefix + name;
   };
 
   const toSelector = (): string => {

src/element.ts

@@ -22,7 +22,9 @@ export function element(
   }
 
   const toString = (): string => {
-    return name ? blockName + delimiters.element + name : blockName;
+    return delimiters.prefix + name
+      ? blockName + delimiters.element + name
+      : blockName;
   };
 
   const toSelector = (): string => {

src/modifier.ts

@@ -32,6 +32,7 @@ export function modifier(
 
   const toString = (): string => {
     return (
+      delimiters.prefix +
       blockName +
       (elementName ? delimiters.element + elementName : '') +
       (modifierString ? delimiters.modifier + modifierString : '')

src/types.ts

@@ -1,4 +1,5 @@
 export interface BEMDelimiters {
+  prefix: string;
   element: string;
   modifier: string;
   modifierValue: string;