Tartufo does not detect secrets in filenames (in the name of the files)

[pmevzek-godaddy]

🐛 Bug Report

It may happen that a secret, like an API key is just a filename or part of a filename.
Voluntarily or involuntarily (bad output, etc.)
This secret is not seen by tartufo.

To Reproduce

Same string is used as a secret inside a file and as a filename. Tartufo sees the secret string
only inside the content of the file, not as the filename.

$ git init test
$ cd test
$ git commit --allow-empty --allow-empty-message -m 'Start'
$ echo "This is a secret: ef55191bd917afe4f2b488c5323c9ab4" > secret.txt
$ touch ef55191bd917afe4f2b488c5323c9ab4.txt
$ git add *
$ git --no-pager diff --cached
diff --git a/ef55191bd917afe4f2b488c5323c9ab4.txt b/ef55191bd917afe4f2b488c5323c9ab4.txt
new file mode 100644
index 0000000..e69de29
diff --git a/secret.txt b/secret.txt
new file mode 100644
index 0000000..d98668e
--- /dev/null
+++ b/secret.txt
@@ -0,0 +1 @@
+This is a secret: ef55191bd917afe4f2b488c5323c9ab4
$ tartufo --json --entropy --regex pre-commit  | jq .
{
  "scan_time": "2021-04-23T17:11:35.828653",
  "project_path": "/private/tmp/test",
  "output_dir": null,
  "excluded_paths": [],
  "excluded_signatures": [],
  "found_issues": [
    {
      "file_path": "secret.txt",
      "matched_string": "ef55191bd917afe4f2b488c5323c9ab4",
      "signature": "c00592a980a844cf229a6c0a5bfec004f1798d9b426021fa97dffde4299558ec",
      "issue_type": "High Entropy",
      "issue_detail": null,
      "diff": "@@ -0,0 +1 @@\n+This is a secret: ef55191bd917afe4f2b488c5323c9ab4\n"
    }
  ]
}
$ git restore --staged secret.txt
$ rm secret.txt
$ git --no-pager diff --cached
diff --git a/ef55191bd917afe4f2b488c5323c9ab4.txt b/ef55191bd917afe4f2b488c5323c9ab4.txt
new file mode 100644
index 0000000..e69de29
$ tartufo --json --entropy --regex pre-commit  | jq .
{
  "scan_time": "2021-04-23T17:12:10.242407",
  "project_path": "/private/tmp/test",
  "output_dir": null,
  "excluded_paths": [],
  "excluded_signatures": [],
  "found_issues": []
}

Expected Behavior

Tartufo should report problems for filenames exactly as for file contents.
Same for directory names of course.

Code Example

See above.

Environment

$ tartufo --version
tartufo, version 2.4.0

[tarkatronic]

Fixed in #259