move NestedWizard logic to Wizzard class

Author: vicheey

packages/core/src/shared/ui/nestedWizardPrompter.ts

@@ -8,19 +8,12 @@ import { StepEstimator, Wizard, WIZARD_BACK, WIZARD_SKIP } from '../wizards/wiza
 import { Prompter, PromptResult } from './prompter'
 
 /**
- * Wraps {@link Wizard} object into its own {@link Prompter}, allowing wizards to use other
- * wizards in their flows.
- *
+ * Wraps {@link Wizard} object into its own {@link Prompter}, allowing wizards to use other wizards in their flows.
+ * This is meant to be used exclusively in createWizardPrompter() method of {@link Wizard} class.
  * @remarks
- *  - This class should only be used inside wizard classes that extend {@link NestedWizard}.
- *  - See examples:
- *     - {@link SingleNestedWizard}
- *     - {@link DoubleNestedWizard}
+ *  - Use createWizardPrompter() method of {@link Wizard} when creating a nested wizard prompter for proper state management.
+ *  - The WizardPrompter class should never be instantiated with directly.
  */
-
-// eslint-disable-next-line @typescript-eslint/naming-convention
-export const WIZARD_PROMPTER = 'WIZARD_PROMPTER'
-
 export class WizardPrompter<T> extends Prompter<T> {
     public get recentItem(): any {
         return undefined
@@ -64,7 +57,7 @@ export class WizardPrompter<T> extends Prompter<T> {
 
         if (this.response === undefined) {
             return WIZARD_BACK as PromptResult<T>
-        } else if (_.isEmpty(this.response)) {
+        } else if (JSON.stringify(this.response) === '{}') {
             return WIZARD_SKIP as PromptResult<T>
         }
 

packages/core/src/shared/ui/wizardPrompter.ts

@@ -16,7 +16,7 @@ export enum ControlSignal {
  * Value for indicating current direction of the wizard
  * Created mainly to support skipping prompters
  */
-export enum DIRECTION {
+export enum Direction {
     Forward,
     Backward,
 }
@@ -48,11 +48,11 @@ export class StateMachineController<TState> {
     private extraSteps = new Map<number, Branch<TState>>()
     private steps: Branch<TState> = []
     private internalStep: number = 0
-    private direction: DIRECTION
+    private direction: Direction
 
     public constructor(private state: TState = {} as TState) {
         this.previousStates = [_.cloneDeep(state)]
-        this.direction = DIRECTION.Forward
+        this.direction = Direction.Forward
     }
 
     public addStep(step: StepFunction<TState>): void {
@@ -82,14 +82,14 @@ export class StateMachineController<TState> {
 
         this.state = this.previousStates.pop()!
         this.internalStep -= 1
-        this.direction = DIRECTION.Backward
+        this.direction = Direction.Backward
     }
 
     protected advanceState(nextState: TState): void {
         this.previousStates.push(this.state)
         this.state = nextState
         this.internalStep += 1
-        this.direction = DIRECTION.Forward
+        this.direction = Direction.Forward
     }
 
     protected detectCycle(step: StepFunction<TState>): TState | undefined {
@@ -122,7 +122,7 @@ export class StateMachineController<TState> {
                 /**
                  * Depending on current wizard direction, skip signal get converted to forward or backward control signal
                  */
-                result.controlSignal = this.direction === DIRECTION.Forward ? undefined : ControlSignal.Back
+                result.controlSignal = this.direction === Direction.Forward ? undefined : ControlSignal.Back
             }
             return result
         } else {

packages/core/src/shared/wizards/stateController.ts

@@ -7,6 +7,8 @@ import { Branch, ControlSignal, StateMachineController, StepFunction } from './s
 import * as _ from 'lodash'
 import { Prompter, PromptResult } from '../../shared/ui/prompter'
 import { PrompterProvider, WizardForm } from './wizardForm'
+import { createHash } from 'crypto'
+import { WizardPrompter } from '../ui/wizardPrompter'
 
 /** Checks if the user response is valid (i.e. not undefined and not a control signal) */
 export function isValidResponse<T>(response: PromptResult<T>): response is T {
@@ -89,6 +91,10 @@ export class Wizard<TState extends Partial<Record<keyof TState, unknown>>> {
     private _exitStep?: StepFunction<TState>
     /** Guards against accidental use of the Wizard before `init()`. */
     private _ready: boolean
+    /**
+     * Map to store memoized wizard instances using SHA-256 hashed keys
+     */
+    private childWizards: Map<string, any> = new Map()
 
     /** Checks that `init()` was performed (if it was defined). */
     private assertReady() {
@@ -99,6 +105,45 @@ export class Wizard<TState extends Partial<Record<keyof TState, unknown>>> {
         }
     }
 
+    /**
+     * Creates a prompter for a wizard instance with memoization.
+     *
+     * @template TWizard - The type of wizard, must extend Wizard<TState>
+     * @template TState - The type of state managed by the wizard
+     *
+     * @param wizardClass - The wizard class constructor
+     * @param args - Constructor arguments for the wizard instance
+     *
+     * @returns A wizard prompter to be used as prompter
+     *
+     * @example
+     * // Create a prompter for SyncWizard
+     * const prompter = this.createWizardPrompter<SyncWizard, SyncParams>(
+     *     SyncWizard,
+     *     template.uri,
+     *     syncUrl
+     * )
+     *
+     * @remarks
+     * - Instances are memoized using a SHA-256 hash of the wizard class name and arguments
+     * - The same wizard instance is reused for identical constructor parameters for restoring wizard prompter
+     *   states during back button click event
+     */
+    protected createWizardPrompter<TWizard extends Wizard<TState>, TState>(
+        wizardClass: new (...args: any[]) => TWizard,
+        ...args: ConstructorParameters<new (...args: any[]) => TWizard>
+    ): Prompter<TState> {
+        const memoizeKey = createHash('sha256')
+            .update(wizardClass.name + JSON.stringify(args))
+            .digest('hex')
+
+        if (!this.childWizards.get(memoizeKey)) {
+            this.childWizards.set(memoizeKey, new wizardClass(...args))
+        }
+
+        return new WizardPrompter(this.childWizards.get(memoizeKey)) as Prompter<TState>
+    }
+
     /**
      * The offset is applied to both the current step and total number of steps. Useful if the wizard is
      * apart of some overarching flow.

packages/core/src/shared/wizards/wizard.ts

@@ -4,7 +4,6 @@
  */
 import * as vscode from 'vscode'
 import { createCommonButtons } from '../../../shared/ui/buttons'
-import { NestedWizard } from '../../../shared/ui/nestedWizardPrompter'
 import { createQuickPick, DataQuickPickItem } from '../../../shared/ui/pickerPrompter'
 import { Wizard } from '../../../shared/wizards/wizard'
 import * as assert from 'assert'
@@ -56,7 +55,7 @@ class ChildWizard extends Wizard<ChildWizardForm> {
     }
 }
 
-class SingleNestedWizard extends NestedWizard<SingleNestedWizardForm> {
+class SingleNestedWizard extends Wizard<SingleNestedWizardForm> {
     constructor() {
         super()
 
@@ -75,7 +74,7 @@ class SingleNestedWizard extends NestedWizard<SingleNestedWizardForm> {
     }
 }
 
-class DoubleNestedWizard extends NestedWizard<DoubleNestedWizardForm> {
+class DoubleNestedWizard extends Wizard<DoubleNestedWizardForm> {
     constructor() {
         super()