Refactor undefined to null for height

packages/uif/src/BaseIndexer.ts

@@ -35,7 +35,7 @@ export abstract class BaseIndexer implements Indexer {
   /**
    * Initializes the indexer. It should return a height that the indexer has
    * synced up to. If the indexer has not synced any data, it should return
-   * undefined.
+   * `null`.
    *
    * This method is expected to read the height that was saved previously with
    * `setSafeHeight`. It shouldn't call `setSafeHeight` itself.
@@ -45,17 +45,17 @@ export abstract class BaseIndexer implements Indexer {
    * Since a root indexer probably doesn't save the height to a database, it
    * can `return this.tick()` instead.
    */
-  abstract initialize(): Promise<number | undefined>
+  protected abstract initialize(): Promise<number | null>
 
   /**
    * Saves the height (most likely to a database). The height given is the
    * smallest height from all parents and what the indexer itself synced to
-   * previously. It can be undefined.
+   * previously. It can be `null`.
    *
    * When `initialize` is called it is expected that it will read the same
    * height that was saved here.
    */
-  protected abstract setSafeHeight(height: number | undefined): Promise<void>
+  protected abstract setSafeHeight(height: number | null): Promise<void>
 
   /**
    * This method should only be implemented for a child indexer.
@@ -66,23 +66,23 @@ export abstract class BaseIndexer implements Indexer {
    * 110. The next time this method will be called with `.update(110, 200)`.
    *
    * @param from The height that the indexer has synced up to previously. Can
-   * be undefined if no data was synced. This value is inclusive so the indexer
+   * be `null` if no data was synced. This value is exclusive so the indexer
    * should not fetch data for this height.
    *
    * @param to The height that the indexer should sync up to. This value is
-   * exclusive so the indexer should fetch data for this height.
+   * inclusive so the indexer should fetch data for this height.
    *
    * @returns The height that the indexer has synced up to. Returning `from`
    * means that the indexer has not synced any data. Returning a value greater
    * than `from` means that the indexer has synced up to that height. Returning
    * a value less than `from` will trigger invalidation down to the returned
-   * value. Returning `undefined` will invalidate all data. Returning a value
+   * value. Returning `null` will invalidate all data. Returning a value
    * greater than `to` is not permitted.
    */
   protected abstract update(
-    from: number | undefined,
+    from: number | null,
     to: number,
-  ): Promise<number | undefined>
+  ): Promise<number | null>
 
   /**
    * This method should only be implemented for a child indexer.
@@ -98,7 +98,7 @@ export abstract class BaseIndexer implements Indexer {
    * steps, you can return a height that is larger than the target height.
    *
    * @param targetHeight The height that the indexer should invalidate down to.
-   * Can be undefined. If it is undefined, the indexer should invalidate all
+   * Can be `null`. If it is `null`, the indexer should invalidate all
    * data.
    *
    * @returns The height that the indexer has invalidated down to. Returning
@@ -107,8 +107,8 @@ export abstract class BaseIndexer implements Indexer {
    * has invalidated down to that height.
    */
   protected abstract invalidate(
-    targetHeight: number | undefined,
-  ): Promise<number | undefined>
+    targetHeight: number | null,
+  ): Promise<number | null>
 
   /**
    * This method should only be implemented for a root indexer.
@@ -117,7 +117,7 @@ export abstract class BaseIndexer implements Indexer {
    * Some good examples of this are: the current time or the last block number.
    *
    * As opposed to `update` and `invalidate`, this method cannot return
-   * `undefined`.
+   * `null`.
    */
   protected abstract tick(): Promise<number>
 
@@ -177,7 +177,7 @@ export abstract class BaseIndexer implements Indexer {
     this.dispatch({ type: 'ChildReady', index })
   }
 
-  notifyUpdate(parent: Indexer, safeHeight: number | undefined): void {
+  notifyUpdate(parent: Indexer, safeHeight: number | null): void {
     this.logger.debug('Someone has updated', {
       parent: parent.constructor.name,
     })

packages/uif/src/Indexer.ts

@@ -6,6 +6,6 @@ export interface UpdateEvent {
 export interface Indexer {
   subscribe(child: Indexer): void
   notifyReady(child: Indexer): void
-  notifyUpdate(parent: Indexer, safeHeight: number | undefined): void
+  notifyUpdate(parent: Indexer, safeHeight: number | null): void
   start(): Promise<void>
 }

packages/uif/src/height.ts

@@ -6,42 +6,36 @@ export const Height = {
   min,
 }
 
-function lt(heightA: number | undefined, heightB: number | undefined): boolean {
+function lt(heightA: number | null, heightB: number | null): boolean {
   if (heightA === heightB) {
     return false
   }
   return !gt(heightA, heightB)
 }
 
-function lte(
-  heightA: number | undefined,
-  heightB: number | undefined,
-): boolean {
+function lte(heightA: number | null, heightB: number | null): boolean {
   return !gt(heightA, heightB)
 }
 
-function gt(heightA: number | undefined, heightB: number | undefined): boolean {
-  if (heightA === undefined) {
+function gt(heightA: number | null, heightB: number | null): boolean {
+  if (heightA === null) {
     return false
   }
-  if (heightB === undefined) {
+  if (heightB === null) {
     return true
   }
   return heightA > heightB
 }
 
-function gte(
-  heightA: number | undefined,
-  heightB: number | undefined,
-): boolean {
+function gte(heightA: number | null, heightB: number | null): boolean {
   return !lt(heightA, heightB)
 }
 
-function min(...heights: (number | undefined)[]): number | undefined {
+function min(...heights: (number | null)[]): number | null {
   if (heights.length === 0) {
-    return undefined
+    return null
   }
-  let minHeight = heights[0]
+  let minHeight = heights[0] ?? null
   for (const height of heights) {
     if (gt(minHeight, height)) {
       minHeight = height

packages/uif/src/reducer/helpers/continueOperations.ts

@@ -96,7 +96,7 @@ export function continueOperations(
     !shouldInvalidate &&
     initializedParents.length > 0 &&
     Height.gt(parentHeight, state.height) &&
-    parentHeight !== undefined
+    parentHeight !== null
 
   if (shouldInvalidate) {
     if (state.invalidateBlocked || state.waiting || state.status !== 'idle') {

packages/uif/src/reducer/types/IndexerAction.ts

@@ -1,13 +1,13 @@
 export interface InitializedAction {
   type: 'Initialized'
-  safeHeight: number | undefined
+  safeHeight: number | null
   childCount: number
 }
 
 export interface ParentUpdatedAction {
   type: 'ParentUpdated'
   index: number
-  safeHeight: number | undefined
+  safeHeight: number | null
 }
 
 export interface ChildReadyAction {
@@ -17,8 +17,8 @@ export interface ChildReadyAction {
 
 export interface UpdateSucceededAction {
   type: 'UpdateSucceeded'
-  from: number | undefined
-  newHeight: number | undefined
+  from: number | null
+  newHeight: number | null
 }
 
 export interface UpdateFailedAction {
@@ -32,7 +32,7 @@ export interface RetryUpdateAction {
 
 export interface InvalidateSucceededAction {
   type: 'InvalidateSucceeded'
-  targetHeight: number | undefined
+  targetHeight: number | null
 }
 
 export interface InvalidateFailedAction {

packages/uif/src/reducer/types/IndexerEffect.ts

@@ -15,12 +15,12 @@ export interface UpdateEffect {
 
 export interface InvalidateEffect {
   type: 'Invalidate'
-  targetHeight: number | undefined
+  targetHeight: number | null
 }
 
 export interface SetSafeHeightEffect {
   type: 'SetSafeHeight'
-  safeHeight: number | undefined
+  safeHeight: number | null
 }
 
 export interface NotifyReadyEffect {

packages/uif/src/reducer/types/IndexerState.ts

@@ -6,20 +6,20 @@ export interface IndexerState {
     | 'invalidating'
     | 'ticking'
     | 'errored'
-  readonly height: number | undefined
-  readonly invalidateToHeight: number | undefined
+  readonly height: number | null
+  readonly invalidateToHeight: number | null
   readonly forceInvalidate: boolean
   // When we change safe height to a lower value we become waiting
   // and we mark all children as not ready
-  readonly safeHeight: number | undefined
+  readonly safeHeight: number | null
   readonly waiting: boolean
   readonly tickScheduled: boolean
   readonly initializedSelf: boolean
   readonly parents: {
     readonly initialized: boolean
     // When the parent changes safeHeight to a lower value
     // we mark them as waiting and will notify them when we're ready
-    readonly safeHeight: number | undefined
+    readonly safeHeight: number | null
     readonly waiting: boolean
   }[]
   readonly children: {