Added nested colors in theme.

src/__tests__/index.spec.js

@@ -38,4 +38,51 @@ describe('makeTheme', () => {
       new Color(colors.red).darken(0.1).toString()
     )
   })
+
+  it('extracts theme structure', () => {
+    const exampleTheme = {
+      background: 'white',
+      color: 'red',
+      ui: {
+        background: 'gray',
+        color: 'red'
+      }
+    }
+
+    const theme = makeTheme(exampleTheme)
+
+    const colorSelector = theme.color
+    expect(colorSelector).toBeA('function')
+    expect(colorSelector.length).toBe(1)
+
+   const uiColorSelector = theme.ui.color
+   expect(uiColorSelector).toBeA('function')
+   expect(uiColorSelector.length).toBe(1)
+
+   const themeFromProvider = {
+     theme: {
+       background: '#FFFFFF',
+       color: '#2A2A2A',
+       ui: {
+         background: '#000000',
+         color: '#9B1919'
+       }
+     }
+   }
+
+   expect(colorSelector(themeFromProvider))
+       .toBe(themeFromProvider.theme.color)
+   expect(uiColorSelector(themeFromProvider))
+       .toBe(themeFromProvider.theme.ui.color)
+
+   const darkerColor = colorSelector.darken(0.1)
+   const lighterUIColor = uiColorSelector.lighten(0.4)
+
+   expect(darkerColor(themeFromProvider)).toBe(
+     new Color(themeFromProvider.theme.color).darken(0.1).toString()
+   )
+   expect(lighterUIColor(themeFromProvider)).toBe(
+     new Color(themeFromProvider.theme.ui.color).lighten(0.4).toString()
+   )
+  })
 })

src/index.js

@@ -1,11 +1,28 @@
 import makeThemeColor from './makeThemeColor'
 
-const makeTheme = (...colors) =>
-  colors.reduce((result, color) => {
-    result[color] = makeThemeColor(color)
+const makeTheme = (theme, ...themePath) => {
+  if (typeof(theme) !== 'object') {
+    // compat mode
+    // make theme object with keys of all arguments
+    theme = [theme, ...themePath].reduce(
+      (result, color) => {
+        result[color] = ''
+        return result
+    }, {})
+    return makeTheme(theme)
+  }   
+
+  themePath = themePath.length ? themePath : ['theme']
+
+  return Object.entries(theme).reduce((result, [key, item]) => {
+    if (typeof(item) === 'object') {
+      result[key] = makeTheme(item, ...themePath, key)
+    } else {
+      result[key] = makeThemeColor(...themePath, key)
+    }
     return result
   }, {})
+} 
 
-export { makeThemeColor }
 
 export default makeTheme

src/makeThemeColor.js

@@ -1,5 +1,10 @@
 import decorateSelector from './decorateSelector'
 
-const makeThemeColor = key => decorateSelector(props => props.theme[key])
+const makeThemeColor = (...propsPath) =>
+  decorateSelector(props => {
+    propsPath.forEach(key => props = props[key])
+    return props
+  })
+
 
 export default makeThemeColor