Replace LinkInterceptor with LinkClickObserver

Follow-up to #382

---

In the same style as [#382][], replace instances of
`LinkInterceptor` with `LinkClickObserver`, making the necessary
interface changes in classes that used to extend
`LinkInterceptorDelegate`.

Conditional logic that was once covered in the `LinkInterceptor` is
moved into the predicate methods of the delegates (for example, the
`FrameController.willFollowLinkToLocation` and
`FrameRedirector.willFollowLinkToLocation`).

Since the recently introduced [FormLinkInterceptor][] was named after
the `LinkInterceptor`, this commit also renames that class (and its call
sites) to match the `LinkClickObserver`-suffix, along with the
`LinkInterceptorDelegate` method structure.

[#382]: #382
[FormLinkInterceptor]: f8a94c5

src/core/frames/frame_controller.ts

@@ -23,7 +23,7 @@ import { ViewDelegate, ViewRenderOptions } from "../view"
 import { getAction, expandURL, urlsAreEqual, locationIsVisitable } from "../url"
 import { FormSubmitObserver, FormSubmitObserverDelegate } from "../../observers/form_submit_observer"
 import { FrameView } from "./frame_view"
-import { LinkInterceptor, LinkInterceptorDelegate } from "./link_interceptor"
+import { LinkClickObserver, LinkClickObserverDelegate } from "../../observers/link_click_observer"
 import { FormLinkClickObserver, FormLinkClickObserverDelegate } from "../../observers/form_link_click_observer"
 import { FrameRenderer } from "./frame_renderer"
 import { session } from "../index"
@@ -39,14 +39,14 @@ export class FrameController
     FormSubmissionDelegate,
     FrameElementDelegate,
     FormLinkClickObserverDelegate,
-    LinkInterceptorDelegate,
+    LinkClickObserverDelegate,
     ViewDelegate<FrameElement, Snapshot<FrameElement>>
 {
   readonly element: FrameElement
   readonly view: FrameView
   readonly appearanceObserver: AppearanceObserver
   readonly formLinkClickObserver: FormLinkClickObserver
-  readonly linkInterceptor: LinkInterceptor
+  readonly linkClickObserver: LinkClickObserver
   readonly formSubmitObserver: FormSubmitObserver
   formSubmission?: FormSubmission
   fetchResponseLoaded = (_fetchResponse: FetchResponse) => {}
@@ -65,7 +65,7 @@ export class FrameController
     this.view = new FrameView(this, this.element)
     this.appearanceObserver = new AppearanceObserver(this, this.element)
     this.formLinkClickObserver = new FormLinkClickObserver(this, this.element)
-    this.linkInterceptor = new LinkInterceptor(this, this.element)
+    this.linkClickObserver = new LinkClickObserver(this, this.element)
     this.restorationIdentifier = uuid()
     this.formSubmitObserver = new FormSubmitObserver(this, this.element)
   }
@@ -79,7 +79,7 @@ export class FrameController
         this.loadSourceURL()
       }
       this.formLinkClickObserver.start()
-      this.linkInterceptor.start()
+      this.linkClickObserver.start()
       this.formSubmitObserver.start()
     }
   }
@@ -89,7 +89,7 @@ export class FrameController
       this.connected = false
       this.appearanceObserver.stop()
       this.formLinkClickObserver.stop()
-      this.linkInterceptor.stop()
+      this.linkClickObserver.stop()
       this.formSubmitObserver.stop()
     }
   }
@@ -180,22 +180,22 @@ export class FrameController
   // Form link click observer delegate
 
   willSubmitFormLinkToLocation(link: Element): boolean {
-    return this.shouldInterceptNavigation(link)
+    return link.closest("turbo-frame") == this.element && this.shouldInterceptNavigation(link)
   }
 
   submittedFormLinkToLocation(link: Element, _location: URL, form: HTMLFormElement): void {
     const frame = this.findFrameElement(link)
     if (frame) form.setAttribute("data-turbo-frame", frame.id)
   }
 
-  // Link interceptor delegate
+  // Link click observer delegate
 
-  shouldInterceptLinkClick(element: Element, _url: string) {
+  willFollowLinkToLocation(element: Element) {
     return this.shouldInterceptNavigation(element)
   }
 
-  linkClickIntercepted(element: Element, url: string) {
-    this.navigateFrame(element, url)
+  followedLinkToLocation(element: Element, location: URL) {
+    this.navigateFrame(element, location.href)
   }
 
   // Form submit observer delegate

src/core/frames/frame_redirector.ts

@@ -1,37 +1,38 @@
 import { FormSubmitObserver, FormSubmitObserverDelegate } from "../../observers/form_submit_observer"
 import { FrameElement } from "../../elements/frame_element"
-import { LinkInterceptor, LinkInterceptorDelegate } from "./link_interceptor"
 import { expandURL, getAction, locationIsVisitable } from "../url"
+import { LinkClickObserver, LinkClickObserverDelegate } from "../../observers/link_click_observer"
+import { session } from "../../index"
 
-export class FrameRedirector implements LinkInterceptorDelegate, FormSubmitObserverDelegate {
+export class FrameRedirector implements LinkClickObserverDelegate, FormSubmitObserverDelegate {
   readonly element: Element
-  readonly linkInterceptor: LinkInterceptor
+  readonly linkClickObserver: LinkClickObserver
   readonly formSubmitObserver: FormSubmitObserver
 
   constructor(element: Element) {
     this.element = element
-    this.linkInterceptor = new LinkInterceptor(this, element)
+    this.linkClickObserver = new LinkClickObserver(this, element)
     this.formSubmitObserver = new FormSubmitObserver(this, element)
   }
 
   start() {
-    this.linkInterceptor.start()
+    this.linkClickObserver.start()
     this.formSubmitObserver.start()
   }
 
   stop() {
-    this.linkInterceptor.stop()
+    this.linkClickObserver.stop()
     this.formSubmitObserver.stop()
   }
 
-  shouldInterceptLinkClick(element: Element, _url: string) {
+  willFollowLinkToLocation(element: Element) {
     return this.shouldRedirect(element)
   }
 
-  linkClickIntercepted(element: Element, url: string) {
+  followedLinkToLocation(element: Element, url: URL) {
     const frame = this.findFrameElement(element)
     if (frame) {
-      frame.delegate.linkClickIntercepted(element, url)
+      frame.delegate.followedLinkToLocation(element, url)
     }
   }
 
@@ -59,8 +60,12 @@ export class FrameRedirector implements LinkInterceptorDelegate, FormSubmitObser
   }
 
   private shouldRedirect(element: Element, submitter?: HTMLElement) {
-    const frame = this.findFrameElement(element, submitter)
-    return frame ? frame != element.closest("turbo-frame") : false
+    if (session.elementIsNavigatable(element) && (!submitter || session.submitterIsNavigatable(submitter))) {
+      const frame = this.findFrameElement(element, submitter)
+      return frame ? frame != element.closest("turbo-frame") : false
+    } else {
+      return false
+    }
   }
 
   private findFrameElement(element: Element, submitter?: HTMLElement) {

src/elements/frame_element.ts

@@ -1,6 +1,6 @@
 import { FetchResponse } from "../http/fetch_response"
 import { Snapshot } from "../core/snapshot"
-import { LinkInterceptorDelegate } from "../core/frames/link_interceptor"
+import { LinkClickObserverDelegate } from "../observers/link_click_observer"
 import { FormSubmitObserverDelegate } from "../observers/form_submit_observer"
 
 export enum FrameLoadingStyle {
@@ -10,7 +10,7 @@ export enum FrameLoadingStyle {
 
 export type FrameElementObservedAttribute = keyof FrameElement & ("disabled" | "complete" | "loading" | "src")
 
-export interface FrameElementDelegate extends LinkInterceptorDelegate, FormSubmitObserverDelegate {
+export interface FrameElementDelegate extends LinkClickObserverDelegate, FormSubmitObserverDelegate {
   connect(): void
   disconnect(): void
   completeChanged(): void

src/observers/form_link_click_observer.ts

@@ -6,20 +6,20 @@ export type FormLinkClickObserverDelegate = {
 }
 
 export class FormLinkClickObserver implements LinkClickObserverDelegate {
-  readonly linkInterceptor: LinkClickObserver
+  readonly linkClickObserver: LinkClickObserver
   readonly delegate: FormLinkClickObserverDelegate
 
   constructor(delegate: FormLinkClickObserverDelegate, element: HTMLElement) {
     this.delegate = delegate
-    this.linkInterceptor = new LinkClickObserver(this, element)
+    this.linkClickObserver = new LinkClickObserver(this, element)
   }
 
   start() {
-    this.linkInterceptor.start()
+    this.linkClickObserver.start()
   }
 
   stop() {
-    this.linkInterceptor.stop()
+    this.linkClickObserver.stop()
   }
 
   willFollowLinkToLocation(link: Element, location: URL, originalEvent: MouseEvent): boolean {