Duplicate Code: Repeated region resolution logic in ResolutionSelector and element-wise coord utilities

[github-actions]

Analysis of commit 846ffc9

Assignee: @copilot

Summary

Two distinct structural duplication patterns were found in the source files:

1. selectResolution and select2DResolution share nearly identical region-computation blocks in both their inner loop and fallback paths — 4 occurrences of the same ~14-line block.
2. roundPixelCoord / floorPixelCoord / ceilPixelCoord are structurally identical element-wise mapping functions differing only in the Math.* operation applied.

---

Pattern 1 — Duplicated region-computation block in ResolutionSelector.ts

• Severity: Medium
• Occurrences: 4 (2 inside each function's loop, 2 in fallback paths)
• Locations:
  • fidnii/src/ResolutionSelector.ts lines 47–59 (selectResolution loop body)
  • fidnii/src/ResolutionSelector.ts lines 74–88 (selectResolution fallback)
  • fidnii/src/ResolutionSelector.ts lines 282–296 (select2DResolution loop body)
  • fidnii/src/ResolutionSelector.ts lines 316–330 (select2DResolution fallback)

Duplicated block (~14 lines, repeated 4×):

const region = clipPlanesToPixelRegion(
  clipPlanes,
  volumeBounds,
  image,           // or lowestImage in fallback
  viewportBounds,
)
const alignedRegion = alignRegionToChunks(region, image)

const dimensions: [number, number, number] = [
  alignedRegion.end[0] - alignedRegion.start[0],
  alignedRegion.end[1] - alignedRegion.start[1],
  alignedRegion.end[2] - alignedRegion.start[2],
]

Root cause: select2DResolution is a near-copy of selectResolution with only the pixel-budget calculation differing (3D voxel count vs. in-plane × slab depth).

Refactoring Recommendation

Extract a shared helper that computes the aligned dimensions for a given resolution image:

function computeAlignedDimensions(
  image: MultiscaleImage,
  clipPlanes: ClipPlanes,
  volumeBounds: VolumeBounds,
  viewportBounds?: VolumeBounds,
): [number, number, number] {
  const region = clipPlanesToPixelRegion(clipPlanes, volumeBounds, image, viewportBounds)
  const aligned = alignRegionToChunks(region, image)
  return [
    aligned.end[0] - aligned.start[0],
    aligned.end[1] - aligned.start[1],
    aligned.end[2] - aligned.start[2],
  ]
}

Then accept a pixelCountFn: (dims: [number, number, number], image: MultiscaleImage) => number callback in a unified selectResolutionWithBudget helper, or simply call computeAlignedDimensions from both functions.

---

Pattern 2 — Structurally identical element-wise pixel-coordinate functions in coordinates.ts

• Severity: Low
• Occurrences: 3
• Locations:
  • fidnii/src/utils/coordinates.ts lines 232–240 (roundPixelCoord)
  • fidnii/src/utils/coordinates.ts lines 248–256 (floorPixelCoord)
  • fidnii/src/utils/coordinates.ts lines 264–272 (ceilPixelCoord)

Duplicated structure (9 lines each):

export function (name)PixelCoord(
  pixelCoord: [number, number, number],
): [number, number, number] {
  return [
    Math.(op)(pixelCoord[0]),
    Math.(op)(pixelCoord[1]),
    Math.(op)(pixelCoord[2]),
  ]
}

Refactoring Recommendation

Introduce a private helper and re-implement:

function mapPixelCoord(
  fn: (v: number) => number,
  coord: [number, number, number],
): [number, number, number] {
  return [fn(coord[0]), fn(coord[1]), fn(coord[2])]
}

export const roundPixelCoord = (c: [number, number, number]) => mapPixelCoord(Math.round, c)
export const floorPixelCoord = (c: [number, number, number]) => mapPixelCoord(Math.floor, c)
export const ceilPixelCoord  = (c: [number, number, number]) => mapPixelCoord(Math.ceil,  c)

This keeps the public API identical while eliminating the structural repetition.

---

Impact Analysis

• Maintainability: Any change to the region-computation logic in selectResolution must be mirrored manually in select2DResolution, and any change to the pixel-budget block must be replicated across both fallback paths.
• Bug Risk: A bug fix applied to one copy will silently leave the other copies broken.
• Code Bloat: ~56 lines of duplicated region-computation code; ~18 lines of duplicated element-wise mapping boilerplate.

Implementation Checklist

• Extract computeAlignedDimensions helper in ResolutionSelector.ts
• Refactor selectResolution and select2DResolution to use it
• Add mapPixelCoord helper in coordinates.ts and simplify the three public wrappers
• Run bunx tsc --noEmit to verify no type errors
• Run bun run check to verify lint/format
• Verify no test regressions with bun run test

Analysis Metadata

• Analyzed Files: 14 source files in fidnii/src/ (excluding test files and workflow files)
• Detection Method: Serena semantic code analysis + symbol body inspection
• Commit: 846ffc9
• Analysis Date: 2026-04-15

Generated by Duplicate Code Detector

To install this agentic workflow, run

gh aw add github/gh-aw/.github/workflows/duplicate-code-detector.md@33cd6c7f1fee588654ef19def2e6a4174be66197