Fix: price horizontal water moves at the water cost

src/mineflayer-specific/movements/movement.ts

@@ -259,10 +259,13 @@ export abstract class Movement {
   /**
    * Ticks to travel `blocks` blocks of flat ground.
    *
-   * The bot sprints when allowed (the fastest way to move), otherwise it walks.
-   * Pass `1` for one straight block, `Math.SQRT2` for one diagonal block, etc.
+   * On land the bot sprints when allowed (the fastest way to move), otherwise it
+   * walks. In water it can do neither, so it is priced at the (much slower) swim
+   * speed, which is why callers pass `inLiquid`. Pass `1` for one straight block,
+   * `Math.SQRT2` for one diagonal block, etc.
    */
-  travelCost (blocks: number): number {
+  travelCost (blocks: number, inLiquid = false): number {
+    if (inLiquid) return blocks * WALK_ONE_IN_WATER_COST
     return blocks * (this.settings.allowSprinting ? SPRINT_ONE_BLOCK_COST : WALK_ONE_BLOCK_COST)
   }
 

src/mineflayer-specific/movements/movementProviders.ts

@@ -48,9 +48,10 @@ export class Forward extends MovementProvider {
   getMoveForward (start: Move, dir: Vec3, neighbors: Move[]): void {
     const pos = start.cachedVec
 
-    let cost = this.travelCost(1) // sprint/walk one block forward
-
-    if (this.getBlockInfo(pos, 0, 0, 0).liquid) cost += this.settings.liquidCost
+    // In water the bot swims (no sprint/walk), so price the block at the water
+    // cost itself rather than land speed + a flat add (which undercharged it).
+    const inLiquid = this.getBlockInfo(pos, 0, 0, 0).liquid
+    let cost = this.travelCost(1, inLiquid)
 
     const blockC = this.getBlockInfo(pos, dir.x, 0, dir.z)
     if (blockC.isInvalid) return // out of range.
@@ -100,16 +101,17 @@ export class Diagonal extends MovementProvider {
   }
 
   getMoveDiagonal (node: Move, dir: Vec3, neighbors: Move[], goal: goals.Goal): void {
-    let cost = this.travelCost(Math.SQRT2) // one diagonal block is sqrt(2) blocks of travel
+    // In water the bot swims (no sprint/walk); price the diagonal at the water
+    // cost, which also scales with the sqrt(2) distance (a flat add did not).
+    const inLiquid = this.getBlockInfo(node, 0, 0, 0).liquid
+    let cost = this.travelCost(Math.SQRT2, inLiquid)
 
     const block0 = this.getBlockInfo(node, dir.x, 0, dir.z)
 
     if (block0.isInvalid) return // out of range.
 
     if (!block0.walkthrough) return
 
-    if (this.getBlockInfo(node, 0, 0, 0).liquid) cost += this.settings.liquidCost
-
     const toBreak: BreakHandler[] = []
     const toPlace: PlaceHandler[] = []
     const block00 = this.getBlockInfo(node, 0, 0, 0)