fix(utils): formatBytes returns NaN undefined and invalid units for negative, sub-1, or non-finite inputs

[hsusul]

Affected Component

src/utils/formatBytes.ts

User Impact

When displaying download progress, cache sizes, or file size measurements in the UI (e.g. progress bars, settings panels, model downloads), negative byte values, non-finite values (like NaN), or sub-1 byte values cause formatBytes to return invalid strings such as "NaN undefined" or "512 undefined".

Exact Reproduction

import { formatBytes } from "./src/utils/formatBytes.ts";

formatBytes(-100); // returns "NaN undefined"
formatBytes(0.5);  // returns "512 undefined"
formatBytes(NaN);  // returns "NaN undefined"

Actual Behavior

• formatBytes(-100) returns "NaN undefined"
• formatBytes(0.5) returns "512 undefined"
• formatBytes(NaN) returns "NaN undefined"

Expected Behavior

• formatBytes should validate that inputs are positive finite numbers (!Number.isFinite(bytes) || bytes <= 0 returns "0 Bytes").
• Sub-kilobyte fractional values (0 < bytes < 1024) should format cleanly under the "Bytes" unit (e.g., "0.5 Bytes").
• The calculated index i should be clamped safely within array bounds [0, sizes.length - 1].

Root Cause

formatBytes only checks bytes === 0 and calculates the log index i = Math.floor(Math.log(bytes) / Math.log(k)). For bytes <= 0 or non-finite inputs, Math.log returns NaN. For 0 < bytes < 1, Math.log is negative so i becomes -1. In both cases, sizes[i] evaluates to undefined.

Proposed Scope

Update formatBytes in src/utils/formatBytes.ts to validate inputs and clamp the unit index, and add unit tests covering these boundary conditions in test/helpers/formatBytes.test.js.

I intend to work on this issue and open a pull request.