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unicodeBOMs

Reports files with Unicode Byte Order Marks (BOMs).

✅ This rule is included in the ts stylistic and stylisticStrict presets.

The Unicode Byte Order Mark (BOM) is a special character (U+FEFF) that can appear at the start of a file to indicate its byte order and encoding. While it can be useful in some contexts, it is generally unnecessary in UTF-8 files and can cause issues with some tools and editors that do not expect it.

Examples

Section titled “Examples”
76// File starts with BOM character (U+FEFAEconsB0valAE <= sp ansty="le--0:#F78C6C;--1:#AA09">82<42sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco"><2;d>
6376// File without BOM chara44AEco61B0v44A09<8242 spans="tyle--0:#D6DEEB;--1:#40">3< 42>

Options

Section titled “Options”

This rule is not configurable.

When Not To Use It

Section titled “When Not To Use It”

If you are working in an environment that specifically requires UTF-8 files to have a BOM, you might choose to disable this rule. However, this is uncommon in modern development, as most tools and editors handle UTF-8 files without a BOM correctly.

Further Reading

Section titled “Further Reading”

Equivalents in Other Linters

Section titled “Equivalents in Other Linters”