url callback for partials (#23)

src/partial.js

@@ -7,12 +7,12 @@ import normalize from './utilities/normalize'
 */
 
 export default (strings, ...vars) => {
-  let { options, url } = normalize(strings, vars)
+  let partial = normalize(strings, vars)
 
   return (strings, ...vars) => {
-    let finalData = normalize(strings, vars)
-    let mergedOptions = { ...options, ...finalData.options }
-    let finalUrl = finalData.url || url
+    let { options, url } = normalize(strings, vars, partial)
+    let mergedOptions = { ...partial.options, ...options }
+    let finalUrl = url || partial.url
 
     return fetch(finalUrl, mergedOptions)
   }

src/utilities/normalize.js

@@ -5,7 +5,7 @@ import processBody from './body'
   return a fetch api compatible object
 */
 
-const buildObjectFromTag = (strings, vars) => {
+const buildObjectFromTag = (strings, vars, partial) => {
   const namespace = 'legible-request-var-'
   return strings
     // First, add namespaced placeholders to elements in `strings`
@@ -32,6 +32,9 @@ const buildObjectFromTag = (strings, vars) => {
       // Get the index at the end of the namespaced string
       const index = parseInt(value.replace(namespace, ''), 10)
       // Return an array of the object key and replaced value from `vars`
+      if (partial.url && key === 'url' && typeof vars[index] === 'function') {
+        return [key, vars[index](partial.url)]
+      }
       return [key, vars[index]]
     })
     // Convert to object
@@ -40,8 +43,8 @@ const buildObjectFromTag = (strings, vars) => {
     }, {})
 }
 
-export default (strings, vars) => {
-  const { url, method, body, ...options } = buildObjectFromTag(strings, vars)
+export default (strings, vars, partial = {}) => {
+  const { url, method, body, ...options } = buildObjectFromTag(strings, vars, partial)
 
   return {
     url,

tests/unit/partial.js

@@ -31,4 +31,19 @@ describe('partial', () => {
     `
     expect(response.country_code).to.equal('US')
   })
+
+  it('passes partial url', async function () {
+    let test = partial`
+      url: /test
+      method: POST
+    `
+
+    await test`
+      url: ${url => {
+        expect(url).to.equal('/test')
+        return 'https://freegeoip.net/json/github.com'
+      }}
+      method: GET
+    `
+  })
 })