pkg/email: add AddAddrContext/RemoveAddrContext

Replace extractBugID function with more general AddAddrContext/RemoveAddrContext.

2 files changed, 88 insertions, 62 deletions

diff --git a/pkg/email/parser.go b/pkg/email/parser.go
index 5d8c54d2c..f0297a588 100644
--- a/pkg/email/parser.go
+++ b/pkg/email/parser.go
@@ -50,11 +50,12 @@ func Parse(r io.Reader, ownEmail string) (*Email, error) {
 	bugID := ""
 	var ccList []string
 	for _, addr := range append(cc, to...) {
-		bugID1, own := extractBugID(addr.Address, ownEmail)
-		if bugID == "" {
-			bugID = bugID1
-		}
-		if !own {
+		cleaned, context, _ := RemoveAddrContext(addr.Address)
+		if cleaned == ownEmail {
+			if bugID == "" {
+				bugID = context
+			}
+		} else {
 			ccList = append(ccList, addr.String())
 		}
 	}
@@ -87,31 +88,39 @@ func Parse(r io.Reader, ownEmail string) (*Email, error) {
 	return email, nil
 }
 
-// extractBugID extracts bug ID encoded in receiver email.
-// We send emails from <something+BUG_ID_HASH@something.com>.
-// from is potentially such email address, canonical is <something@something.com>.
-// This function returns BUG_ID_HASH, or an empty string if from does not contain
-// the hash or is different from canonical.
-func extractBugID(from, canonical string) (string, bool) {
-	if email, err := mail.ParseAddress(canonical); err == nil {
-		canonical = email.Address
-	}
-	canonical = strings.ToLower(canonical)
-	plusPos := strings.IndexByte(from, '+')
-	if plusPos == -1 {
-		return "", strings.ToLower(from) == canonical
-	}
-	atPos := strings.IndexByte(from[plusPos:], '@')
-	if atPos == -1 {
-		return "", false
-	}
-	user := from[:plusPos]
-	domain := from[plusPos+atPos:]
-	hash := from[plusPos+1 : plusPos+atPos]
-	if strings.ToLower(user+domain) != canonical {
-		return "", false
-	}
-	return hash, true
+// AddAddrContext embeds context into local part of the provided email address using '+'.
+// Returns the resulting email address.
+func AddAddrContext(email, context string) (string, error) {
+	addr, err := mail.ParseAddress(email)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse %q as email: %v", email, err)
+	}
+	at := strings.IndexByte(addr.Address, '@')
+	if at == -1 {
+		return "", fmt.Errorf("failed to parse %q as email: no @", email)
+	}
+	addr.Address = addr.Address[:at] + "+" + context + addr.Address[at:]
+	return addr.String(), nil
+}
+
+// RemoveAddrContext extracts context after '+' from the local part of the provided email address.
+// Returns address without the context and the context.
+func RemoveAddrContext(email string) (string, string, error) {
+	addr, err := mail.ParseAddress(email)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to parse %q as email: %v", email, err)
+	}
+	at := strings.IndexByte(addr.Address, '@')
+	if at == -1 {
+		return "", "", fmt.Errorf("failed to parse %q as email: no @", email)
+	}
+	plus := strings.LastIndexByte(addr.Address[:at], '+')
+	if plus == -1 {
+		return email, "", nil
+	}
+	context := addr.Address[plus+1 : at]
+	addr.Address = addr.Address[:plus] + addr.Address[at:]
+	return addr.String(), context, nil
 }
 
 // extractCommand extracts command to syzbot from email body.
diff --git a/pkg/email/parser_test.go b/pkg/email/parser_test.go
index 7b2aa9a0f..d05a597be 100644
--- a/pkg/email/parser_test.go
+++ b/pkg/email/parser_test.go
@@ -23,16 +23,55 @@ func TestExtractCommand(t *testing.T) {
 	}
 }
 
-func TestExtractBugID(t *testing.T) {
-	for i, test := range extractBugIDTests {
-		t.Run(fmt.Sprint(i), func(t *testing.T) {
-			bugID, own := extractBugID(test.email, `"Foo Bar" <foo@bar.com>`)
-			if bugID != test.bugID || own != test.own {
-				t.Logf("expect: own=%v %q", test.own, test.bugID)
-				t.Logf("got   : own=%v %q", test.own, bugID)
-				t.Fail()
-			}
-		})
+func TestAddRemoveAddrContext(t *testing.T) {
+	email := `"Foo Bar" <foo@bar.com>`
+	email00, context00, err := RemoveAddrContext(email)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if email != email00 {
+		t.Fatalf("want: %q, got %q", email, email00)
+	}
+	if context00 != "" {
+		t.Fatalf("want context: %q, got %q", "", context00)
+	}
+	context1 := "context1"
+	email1, err := AddAddrContext(email, context1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want1 := `"Foo Bar" <foo+context1@bar.com>`
+	if want1 != email1 {
+		t.Fatalf("want: %q, got %q", want1, email1)
+	}
+	context2 := "context2"
+	email2, err := AddAddrContext(email1, context2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want2 := `"Foo Bar" <foo+context1+context2@bar.com>`
+	if want2 != email2 {
+		t.Fatalf("want: %q, got %q", want2, email2)
+	}
+	email1, context20, err := RemoveAddrContext(email2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want1 != email1 {
+		t.Fatalf("want: %q, got %q", want1, email1)
+	}
+	if context2 != context20 {
+		t.Fatalf("want context: %q, got %q", context2, context20)
+	}
+	email0, context10, err := RemoveAddrContext(email1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if email != email0 {
+		t.Fatalf("want: %q, got %q", email, email0)
+	}
+	if context1 != context10 {
+		t.Fatalf("want context: %q, got %q", context1, context10)
 	}
 }
 
@@ -86,28 +125,6 @@ line 2
 	},
 }
 
-var extractBugIDTests = []struct {
-	email string
-	bugID string
-	own   bool
-}{
-	{
-		`foo@bar.com`,
-		``,
-		true,
-	},
-	{
-		`foo+123@baz.com`,
-		``,
-		false,
-	},
-	{
-		`foo+123@bar.com`,
-		`123`,
-		true,
-	},
-}
-
 var parseTests = []struct {
 	email string
 	res   *Email