upsun · pjcdawkins · Jul 22, 2025 · Jul 22, 2025
diff --git a/pkg/files/files.go b/pkg/files/files.go
@@ -29,6 +29,7 @@ func Clean(files []FileData) []FileData {
 	for i := range files {
 		files[i].Content = RemoveComments(files[i].Name, files[i].Content)
 		files[i].Content = ReplaceSecrets(files[i].Content, "[REDACTED]")
+		files[i].Content = ReplaceEmails(files[i].Content, "redacted@example.org")
 		files[i].Cleaned = true
 	}
 	return files

diff --git a/pkg/files/redact_emails.go b/pkg/files/redact_emails.go
@@ -0,0 +1,8 @@
+package files
+
+import (
+	"regexp"
+)
+
+// ReplaceEmails tries to detect email addresses in the subject string and then replaces them.
+var ReplaceEmails = regexp.MustCompile(`[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}`).ReplaceAllString
diff --git a/pkg/files/redact_emails_test.go b/pkg/files/redact_emails_test.go
@@ -0,0 +1,68 @@
+package files
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReplaceEmails(t *testing.T) {
+	cases := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "Single email",
+			input:    "Contact: john.doe@example.com for support",
+			expected: "Contact: redacted@example.org for support",
+		},
+		{
+			name:     "Multiple emails",
+			input:    "Email admin@company.org or support@help.net",
+			expected: "Email redacted@example.org or redacted@example.org",
+		},
+		{
+			name: "Email in code comment",
+			input: `# Contact maintainer at maintainer@project.dev
+			func main() {`,
+			expected: `# Contact maintainer at redacted@example.org
+			func main() {`,
+		},
+		{
+			name: "Email in config file",
+			input: `smtp:
+  username: noreply@company.com
+  password: secret123`,
+			expected: `smtp:
+  username: redacted@example.org
+  password: secret123`,
+		},
+		{
+			name:     "Email with plus sign",
+			input:    "test+tag@gmail.com is valid",
+			expected: "redacted@example.org is valid",
+		},
+		{
+			name:     "Email with numbers and dots",
+			input:    "user.123@sub.domain.co.uk works fine",
+			expected: "redacted@example.org works fine",
+		},
+		{
+			name:     "No emails",
+			input:    "This text has no email addresses",
+			expected: "This text has no email addresses",
+		},
+		{
+			name:     "Almost email but invalid",
+			input:    "Not an email: @domain.com or user@ or .com",
+			expected: "Not an email: @domain.com or user@ or .com",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			assert.Equal(t, c.expected, ReplaceEmails(c.input, "redacted@example.org"))
+		})
+	}
+}
diff --git a/pkg/files/secrets.go → pkg/files/redact_secrets.go b/pkg/files/secrets.go → pkg/files/redact_secrets.go
diff --git a/pkg/files/secrets_test.go → pkg/files/redact_secrets_test.go b/pkg/files/secrets_test.go → pkg/files/redact_secrets_test.go