feat(abstract): move forward in history

diff --git a/__tests__/abstract.spec.js b/__tests__/abstract.spec.js
index e0cb613f8e5ffa7cc114e5241220c86a570ee8d4..c490457c597aedc8735fc18940a09ed452b91c37 100644 (file)
--- a/__tests__/abstract.spec.js
+++ b/__tests__/abstract.spec.js
@@ -1,4 +1,5 @@
 // @ts-check
+
 require('./helper')
 const expect = require('expect')
 const { AbstractHistory } = require('../src/history/abstract')
@@ -29,17 +30,19 @@ const normaliezedLoc2 = {
 describe('Abstract/in memory history', () => {
   it('starts at /', () => {
     const history = new AbstractHistory()
+    expect(history.location).toEqual(START)
     expect(history.location).toEqual({
       fullPath: '/',
       path: '/',
       query: {},
       hash: '',
     })
+    expect(history.queue).toHaveLength(1)
   })
 
   it('can push a location', () => {
     const history = new AbstractHistory()
-    // normalized version
+    // partial version
     history.push({ path: '/somewhere', hash: '#hey', query: { foo: 'foo' } })
     expect(history.location).toEqual({
       fullPath: '/somewhere?foo=foo#hey',
@@ -65,13 +68,12 @@ describe('Abstract/in memory history', () => {
 
   it('add entries to the queue', () => {
     const history = new AbstractHistory()
-    expect(history.queue).toHaveLength(0)
     history.push(loc)
-    expect(history.queue).toHaveLength(1)
-    expect(history.queue[0]).toEqual(normaliezedLoc)
-    history.push(loc2)
     expect(history.queue).toHaveLength(2)
-    expect(history.queue[1]).toEqual(normaliezedLoc2)
+    expect(history.queue[1]).toEqual(normaliezedLoc)
+    history.push(loc2)
+    expect(history.queue).toHaveLength(3)
+    expect(history.queue[2]).toEqual(normaliezedLoc2)
   })
 
   it('can go back', () => {
@@ -79,17 +81,51 @@ describe('Abstract/in memory history', () => {
     history.push(loc)
     history.push(loc2)
     history.back()
-    expect(history.queue).toHaveLength(1)
+    expect(history.queue).toHaveLength(3)
     expect(history.location).toEqual(normaliezedLoc)
     history.back()
-    expect(history.queue).toHaveLength(0)
+    expect(history.queue).toHaveLength(3)
+    expect(history.location).toEqual(START)
+  })
+
+  it('does nothing with back if queue contains only one element', () => {
+    const history = new AbstractHistory()
+    history.back()
+    expect(history.location).toEqual(START)
+  })
+
+  it('does nothing with forward if at end of log', () => {
+    const history = new AbstractHistory()
+    history.forward()
+    expect(history.location).toEqual(START)
+  })
+
+  it('can moves back and forth in history queue', () => {
+    const history = new AbstractHistory()
+    history.push(loc)
+    history.push(loc2)
+    history.back()
+    history.back()
     expect(history.location).toEqual(START)
+    history.forward()
+    expect(history.location).toEqual(normaliezedLoc)
+    history.forward()
+    expect(history.location).toEqual(normaliezedLoc2)
   })
 
-  it('does nothing with back if queue is empty', () => {
+  it('can push in the middle of the history', () => {
     const history = new AbstractHistory()
+    history.push(loc)
+    history.push(loc2)
+    history.back()
     history.back()
     expect(history.location).toEqual(START)
+    history.push(loc2)
+    expect(history.queue).toHaveLength(2)
+    expect(history.location).toEqual(normaliezedLoc2)
+    // does nothing
+    history.forward()
+    expect(history.queue).toHaveLength(2)
+    expect(history.location).toEqual(normaliezedLoc2)
   })
-  it('does nothing with forward if at end of log', () => {})
 })

diff --git a/src/history/abstract.ts b/src/history/abstract.ts
index 483b82b17c41b7d69875783eed3e187e73b7d94d..2b318321892ac4205fa4bc9d28c3d3e246e79054 100644 (file)
--- a/src/history/abstract.ts
+++ b/src/history/abstract.ts
@@ -8,10 +8,10 @@ export class AbstractHistory extends BaseHistory {
   // private _listeners: NavigationCallback[] = []
   private teardowns: Array<() => void> = []
   public queue: HistoryLocationNormalized[] = [START]
+  public position: number = 0
 
   constructor() {
     super()
-    debugger
   }
 
   // TODO: is this necessary
@@ -29,20 +29,30 @@ export class AbstractHistory extends BaseHistory {
   }
 
   get location() {
-    console.log('read location', this.queue)
-    return this.queue[this.queue.length - 1]
+    return this.queue[this.position]
   }
 
   set location(location: HistoryLocationNormalized) {
     // super() call tries to push before the array is created
-    console.log('set location', location)
     if (!this.queue) this.queue = []
-    // TODO: handle in the middle
-    this.queue.push(location)
+    // move the queue cursor forward
+    this.position++
+    if (this.position === this.queue.length) {
+      // we are at the end, we can simply append a new entry
+      this.queue.push(location)
+    } else {
+      // we are in the middle, we remove everything from here in the queue
+      this.queue.splice(this.position)
+      this.queue.push(location)
+    }
   }
 
   back() {
-    this.queue.pop()
+    if (this.position > 0) this.position--
+  }
+
+  forward() {
+    if (this.position < this.queue.length - 1) this.position++
   }
 
   destroy() {

diff --git a/src/history/base.ts b/src/history/base.ts
index caea1e0b92ec7eddd844dd41ebc78655ba54bbd3..c97ef71c5120e30c026b72e5420ae46bcbe50809 100644 (file)
--- a/src/history/base.ts
+++ b/src/history/base.ts
@@ -85,6 +85,13 @@ export abstract class BaseHistory {
    */
   abstract back(): void
 
+  /**
+   * Goes forward in history log. Should trigger any listener added via
+   * `listen`. If we are on the last entry, behaviour may change depending
+   * on implementation
+   */
+  abstract forward(): void
+
   /**
    * Notifies back whenever the location changes due to user interactions
    * outside of the applicaiton. For example, going back/forward on a

diff --git a/src/history/html5.ts b/src/history/html5.ts
index 1a111c4a345e7f88588d017147f1aacb2ca64475..50e056851277b70589af63f2b20a5ceb7c61b70a 100644 (file)
--- a/src/history/html5.ts
+++ b/src/history/html5.ts
@@ -95,6 +95,10 @@ export class HTML5History extends BaseHistory {
     // TODO: do not trigger listen
     this.history.back()
   }
+  forward() {
+    // TODO: do not trigger listen
+    this.history.forward()
+  }
 
   listen(callback: NavigationCallback) {
     // settup the listener and prepare teardown callbacks