Bearer scan --diff fails with broken pipe when line too long

[chasay]

Description & Reproduction

When running Bearer with the --diff option and the scanner encounters an error it will return a Error: signal: broken pipe. This is because the error is not checked before returning from the parseDiff function.

Example command: go run ./cmd/bearer/main.go scan ~/code/repo-with-long-line-diff --diff

An example error would be a diff that contains a line longer than the MaxScanTokenSize. (64 * 1024 bytes). With this additional code, the returned error will be Error: bufio.Scanner: token too long.

Expected Behavior

The scan completes successfully.

Actual Behavior

> go run ./cmd/bearer/main.go scan ~/code/repo/ --diff
Analyzing codebase
⠹  (58264/-) [0s]
Loading rules
Scanning target ~/code/repo/
2024-02-21 16:45:28 ERR Git discovery failed process=main
Error: bufio.Scanner: token too long
exit status 1

Possible Fix

Proposed PR to address error

Instead of a bufio.Scanner use a Reader. Looks like you might have some utils that handle this already.

Your Environment

• Operating System and version: Mac and Linux
• Output of 'bearer version':

> go run ./cmd/bearer/main.go version
bearer version dev, build devSHA

> git log --oneline
0b4ecc08 (HEAD -> fix/return-parse-diff-scan-error, me/fix/return-parse-diff-scan-error) fix: return scan error if exists in parseDiff func
b3942b41 (origin/main, origin/HEAD, main) fix(golang): handle sprintf properly (#1503)

bearer version: 0.00.0
sha: xxx