feat: include submitter info.

Buttons allow you to overwrite a forms `method` with the `formmethod`
attribute. `buildRequest` now incorporates submitter info when
determining the submit requests method.

src/index.ts

@@ -65,6 +65,9 @@ export type RemoteFormHandler = (form: HTMLFormElement, kicker: Kicker, req: Sim
 // element.
 type Installable = string | HTMLFormElement
 
+// Any element that submits a <form>
+type HTMLSubmitElement = HTMLButtonElement | HTMLInputElement
+
 let formHandlers: Map<Installable, RemoteFormHandler[]>
 type Handler = (form: HTMLFormElement) => void
 
@@ -133,7 +136,16 @@ function handleSubmit(event: Event) {
     return
   }
 
-  const req = buildRequest(form)
+  let submitter
+
+  if (event instanceof SubmitEvent) {
+    submitter = event.submitter as HTMLSubmitElement
+  } else {
+    submitter = null
+  }
+
+  const req = buildRequest(form, submitter)
+
   const [kickerPromise, ultimateResolve, ultimateReject] = makeDeferred<SimpleResponse>()
 
   event.preventDefault()
@@ -202,9 +214,9 @@ async function processHandlers(
   return kickerWasCalled
 }
 
-function buildRequest(form: HTMLFormElement): SimpleRequest {
+function buildRequest(form: HTMLFormElement, submitter: HTMLSubmitElement | null): SimpleRequest {
   const req: SimpleRequest = {
-    method: form.method || 'GET',
+    method: submitter?.formMethod || form.method || 'GET',
     url: form.action,
     headers: new Headers({'X-Requested-With': 'XMLHttpRequest'}),
     body: null

test/test.js

@@ -164,4 +164,15 @@ describe('remoteForm', function () {
     assert.isFalse(handlerCalled)
     document.removeEventListener('submit', defaultPreventHandler, {capture: true})
   })
+
+  it('overwrites form method with buttons formmethod', function (done) {
+    remoteForm(htmlForm, async (form, wants, req) => {
+      assert.equal(req.method.toUpperCase(), 'GET')
+      done()
+    })
+
+    const button = document.querySelector('button[type=submit]')
+    button.formMethod = 'get'
+    button.click()
+  })
 })