denoland-deno/docs/tools/formatter.md

Code formatter

Deno ships with a built in code formatter that auto-formats TypeScript and JavaScript code.

# format all JS/TS files in the current directory and subdirectories
deno fmt
# format specific files
deno fmt myfile1.ts myfile2.ts
# check if all the JS/TS files in the current directory and subdirectories are formatted
deno fmt --check
# format stdin and write to stdout
cat file.ts | deno fmt -

Ignore formatting code by preceding it with a // deno-fmt-ignore comment:

// deno-fmt-ignore
export const identity = [
    1, 0, 0,
    0, 1, 0,
    0, 0, 1,
];

Or ignore an entire file by adding a // deno-fmt-ignore-file comment at the top of the file.