What edge cases (negative, NaN, Infinity) are tested?

The repository tests several edge cases for invalid inputs and numeric edge cases:

Invalid inputs that throw errors [test.js:L1-L40]:

• Empty strings and non-numeric strings (prettyBytes(''), prettyBytes('1'))
• Number.NaN
• Boolean values (true)
• Number.POSITIVE_INFINITY and Number.NEGATIVE_INFINITY
• null
• Negative fixedWidth values (e.g., -1, -5)
• Non-integer fixedWidth values (e.g., 1.5, 3.5)
• Invalid fixedWidth types (e.g., strings like '10')
• fixedWidth values exceeding Number.MAX_SAFE_INTEGER

Negative numbers (valid, no error) [test.js:L55-L61]:

• prettyBytes(-0.4) → '-0.4 B'
• prettyBytes(-0.7) → '-0.7 B'
• prettyBytes(-10.1) → '-10.1 B'
• prettyBytes(-999) → '-999 B'
• prettyBytes(-1001) → '-1 kB'
• Also tested with bigint variants like -999n, -1001n

Special zero case with signed option [test.js:L281]:

• prettyBytes(0, {fixedWidth: 8, signed: true}) → ' 0 B' (space prefix instead of plus sign for alignment)

The main validation occurs in [index.js:L124-L127], which throws a TypeError if the input is not a finite number or bigint.

FOLLOW_UPS:

• How does prettyBytes handle the signed option for positive numbers?
• What are the different unit systems (BYTE_UNITS, BIT_UNITS, etc.)?
• How does the locale option affect output formatting?