[Autofill Assistant] Refactor field formatter

This CL refactors the field formatter such that non-integer keys are
also supported. This is in preparation for an upcoming CL where this
will be required.

Bug: b/145043394
Change-Id: I603ea66b2ef338d43c263cfa00031eb11dda565d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2235615
Commit-Queue: Clemens Arbesser <arbesser@google.com>
Reviewed-by: Sandro Maggi <sandromaggi@google.com>
Cr-Commit-Position: refs/heads/master@{#777327}

components/autofill_assistant/browser/BUILD.gn

@@ -84,8 +84,6 @@ jumbo_static_library("browser") {
     "actions/wait_for_dom_action.h",
     "actions/wait_for_navigation_action.cc",
     "actions/wait_for_navigation_action.h",
-    "autofill_field_formatter.cc",
-    "autofill_field_formatter.h",
     "basic_interactions.cc",
     "basic_interactions.h",
     "batch_element_checker.cc",
@@ -115,6 +113,8 @@ jumbo_static_library("browser") {
     "event_handler.h",
     "features.cc",
     "features.h",
+    "field_formatter.cc",
+    "field_formatter.h",
     "generic_ui_java_generated_enums.h",
     "info_box.cc",
     "info_box.h",
@@ -254,7 +254,6 @@ source_set("unit_tests") {
     "actions/use_credit_card_action_unittest.cc",
     "actions/wait_for_document_action_unittest.cc",
     "actions/wait_for_dom_action_unittest.cc",
-    "autofill_field_formatter_unittest.cc",
     "basic_interactions_unittest.cc",
     "batch_element_checker_unittest.cc",
     "controller_unittest.cc",
@@ -262,6 +261,7 @@ source_set("unit_tests") {
     "element_area_unittest.cc",
     "element_precondition_unittest.cc",
     "event_handler_unittest.cc",
+    "field_formatter_unittest.cc",
     "protocol_utils_unittest.cc",
     "retry_timer_unittest.cc",
     "script_executor_unittest.cc",

components/autofill_assistant/browser/actions/fallback_handler/required_fields_fallback_handler.cc

@@ -11,9 +11,9 @@
 #include "base/callback.h"
 #include "base/optional.h"
 #include "components/autofill_assistant/browser/actions/action_delegate.h"
-#include "components/autofill_assistant/browser/autofill_field_formatter.h"
 #include "components/autofill_assistant/browser/batch_element_checker.h"
 #include "components/autofill_assistant/browser/client_status.h"
+#include "components/autofill_assistant/browser/field_formatter.h"
 
 namespace autofill_assistant {
 namespace {
@@ -51,7 +51,7 @@ RequiredFieldsFallbackHandler::~RequiredFieldsFallbackHandler() = default;
 
 RequiredFieldsFallbackHandler::RequiredFieldsFallbackHandler(
     const std::vector<RequiredField>& required_fields,
-    const std::map<int, std::string>& fallback_values,
+    const std::map<std::string, std::string>& fallback_values,
     ActionDelegate* delegate)
     : required_fields_(required_fields),
       fallback_values_(fallback_values),
@@ -154,8 +154,8 @@ void RequiredFieldsFallbackHandler::OnCheckRequiredFieldsDone(
       continue;
     }
 
-    if (autofill_field_formatter::FormatString(required_field.value_expression,
-                                               fallback_values_)
+    if (field_formatter::FormatAutofillString(required_field.value_expression,
+                                              fallback_values_)
             .has_value()) {
       has_fallbacks = true;
     } else {
@@ -192,7 +192,7 @@ void RequiredFieldsFallbackHandler::SetFallbackFieldValuesSequentially(
 
   // Set the next field to its fallback value.
   const RequiredField& required_field = required_fields_[required_fields_index];
-  auto fallback_value = autofill_field_formatter::FormatString(
+  auto fallback_value = field_formatter::FormatAutofillString(
       required_field.value_expression, fallback_values_);
   if (!fallback_value.has_value()) {
     VLOG(3) << "No fallback for " << required_field.selector;

components/autofill_assistant/browser/actions/fallback_handler/required_fields_fallback_handler.h

@@ -28,7 +28,7 @@ class RequiredFieldsFallbackHandler {
  public:
   explicit RequiredFieldsFallbackHandler(
       const std::vector<RequiredField>& required_fields,
-      const std::map<int, std::string>& fallback_values,
+      const std::map<std::string, std::string>& fallback_values,
       ActionDelegate* delegate);
 
   ~RequiredFieldsFallbackHandler();
@@ -87,7 +87,7 @@ class RequiredFieldsFallbackHandler {
   ClientStatus client_status_;
 
   std::vector<RequiredField> required_fields_;
-  std::map<int, std::string> fallback_values_;
+  std::map<std::string, std::string> fallback_values_;
   base::OnceCallback<void(const ClientStatus&,
                           const base::Optional<ClientStatus>&)>
       status_update_callback_;

components/autofill_assistant/browser/actions/fallback_handler/required_fields_fallback_handler_unittest.cc

@@ -84,12 +84,14 @@ TEST_F(RequiredFieldsFallbackHandlerTest,
       CreateRequiredField("52", {"#card_number"}),
       CreateRequiredField("-3", {"#card_network"})};
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL),
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL)),
       "John Doe");
-  fallback_values.emplace(
-      static_cast<int>(AutofillFormatProto::CREDIT_CARD_NETWORK), "");
+  fallback_values.emplace(base::NumberToString(static_cast<int>(
+                              AutofillFormatProto::CREDIT_CARD_NETWORK)),
+                          "");
 
   RequiredFieldsFallbackHandler fallback_handler(
       required_fields, fallback_values, &mock_action_delegate_);
@@ -144,13 +146,14 @@ TEST_F(RequiredFieldsFallbackHandlerTest, AddsFirstFieldFillingError) {
       CreateRequiredField("51", {"#card_name"}),
       CreateRequiredField("52", {"#card_number"})};
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL),
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL)),
       "John Doe");
-  fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NUMBER),
-      "4111111111111111");
+  fallback_values.emplace(base::NumberToString(static_cast<int>(
+                              autofill::ServerFieldType::CREDIT_CARD_NUMBER)),
+                          "4111111111111111");
 
   RequiredFieldsFallbackHandler fallback_handler(
       required_fields, fallback_values, &mock_action_delegate_);
@@ -222,9 +225,10 @@ TEST_F(RequiredFieldsFallbackHandlerTest, FillsEmptyRequiredField) {
   std::vector<RequiredField> required_fields = {
       CreateRequiredField("51", {"#card_name"})};
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL),
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL)),
       "John Doe");
 
   RequiredFieldsFallbackHandler fallback_handler(
@@ -253,9 +257,10 @@ TEST_F(RequiredFieldsFallbackHandlerTest, FallsBackForForcedFilledField) {
       CreateRequiredField("51", {"#card_name"})};
   required_fields[0].forced = true;
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL),
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_NAME_FULL)),
       "John Doe");
 
   RequiredFieldsFallbackHandler fallback_handler(
@@ -328,11 +333,14 @@ TEST_F(RequiredFieldsFallbackHandlerTest, FillsFieldWithPattern) {
   std::vector<RequiredField> required_fields = {
       CreateRequiredField("${53}/${55}", {"#card_expiry"})};
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_MONTH), "08");
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_MONTH)),
+      "08");
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_4_DIGIT_YEAR),
+      base::NumberToString(static_cast<int>(
+          autofill::ServerFieldType::CREDIT_CARD_EXP_4_DIGIT_YEAR)),
       "2050");
 
   RequiredFieldsFallbackHandler fallback_handler(
@@ -361,9 +369,10 @@ TEST_F(RequiredFieldsFallbackHandlerTest,
       CreateRequiredField("53", {"#card_expiry"}),
       CreateRequiredField("-3", {"#card_network"})};
 
-  std::map<int, std::string> fallback_values;
-  fallback_values.emplace(
-      static_cast<int>(AutofillFormatProto::CREDIT_CARD_NETWORK), "");
+  std::map<std::string, std::string> fallback_values;
+  fallback_values.emplace(base::NumberToString(static_cast<int>(
+                              AutofillFormatProto::CREDIT_CARD_NETWORK)),
+                          "");
 
   RequiredFieldsFallbackHandler fallback_handler(
       required_fields, fallback_values, &mock_action_delegate_);
@@ -408,35 +417,6 @@ TEST_F(RequiredFieldsFallbackHandlerTest,
                                                   std::move(callback));
 }
 
-TEST_F(RequiredFieldsFallbackHandlerTest, IgnoresNonIntegerKeys) {
-  EXPECT_CALL(mock_web_controller_, OnGetFieldValue(_, _))
-      .WillOnce(RunOnceCallback<1>(OkClientStatus(), ""));
-  Expectation set_value =
-      EXPECT_CALL(mock_action_delegate_,
-                  OnSetFieldValue(Eq(Selector({"#card_expiry"})), "${KEY}", _))
-          .WillOnce(RunOnceCallback<2>(OkClientStatus()));
-  EXPECT_CALL(mock_web_controller_, OnGetFieldValue(_, _))
-      .After(set_value)
-      .WillOnce(RunOnceCallback<1>(OkClientStatus(), "not empty"));
-
-  std::vector<RequiredField> required_fields = {
-      CreateRequiredField("${KEY}", {"#card_expiry"})};
-
-  RequiredFieldsFallbackHandler fallback_handler(required_fields, {},
-                                                 &mock_action_delegate_);
-
-  base::OnceCallback<void(const ClientStatus&,
-                          const base::Optional<ClientStatus>&)>
-      callback =
-          base::BindOnce([](const ClientStatus& status,
-                            const base::Optional<ClientStatus>& detail_status) {
-            EXPECT_EQ(status.proto_status(), ACTION_APPLIED);
-          });
-
-  fallback_handler.CheckAndFallbackRequiredFields(OkClientStatus(),
-                                                  std::move(callback));
-}
-
 TEST_F(RequiredFieldsFallbackHandlerTest, ClicksOnCustomDropdown) {
   EXPECT_CALL(mock_web_controller_, OnGetFieldValue(_, _)).Times(0);
   EXPECT_CALL(mock_action_delegate_, OnSetFieldValue(_, _, _)).Times(0);
@@ -458,9 +438,11 @@ TEST_F(RequiredFieldsFallbackHandlerTest, ClicksOnCustomDropdown) {
       CreateRequiredField("53", {"#card_expiry"})};
   required_fields[0].fallback_click_element = Selector({".option"});
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_MONTH), "08");
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_MONTH)),
+      "08");
 
   RequiredFieldsFallbackHandler fallback_handler(
       required_fields, fallback_values, &mock_action_delegate_);
@@ -498,9 +480,11 @@ TEST_F(RequiredFieldsFallbackHandlerTest, CustomDropdownClicksStopOnError) {
       CreateRequiredField("53", {"#card_expiry"})};
   required_fields[0].fallback_click_element = Selector({".option"});
 
-  std::map<int, std::string> fallback_values;
+  std::map<std::string, std::string> fallback_values;
   fallback_values.emplace(
-      static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_MONTH), "08");
+      base::NumberToString(
+          static_cast<int>(autofill::ServerFieldType::CREDIT_CARD_EXP_MONTH)),
+      "08");
 
   RequiredFieldsFallbackHandler fallback_handler(
       required_fields, fallback_values, &mock_action_delegate_);

components/autofill_assistant/browser/actions/use_address_action.cc

@@ -15,8 +15,8 @@
 #include "components/autofill_assistant/browser/actions/action_delegate.h"
 #include "components/autofill_assistant/browser/actions/fallback_handler/required_field.h"
 #include "components/autofill_assistant/browser/actions/fallback_handler/required_fields_fallback_handler.h"
-#include "components/autofill_assistant/browser/autofill_field_formatter.h"
 #include "components/autofill_assistant/browser/client_status.h"
+#include "components/autofill_assistant/browser/field_formatter.h"
 #include "components/autofill_assistant/browser/user_model.h"
 #include "components/autofill_assistant/browser/value_util.h"
 
@@ -173,8 +173,8 @@ void UseAddressAction::ExecuteFallback(const ClientStatus& status) {
   DCHECK(fallback_handler_ == nullptr);
   fallback_handler_ = std::make_unique<RequiredFieldsFallbackHandler>(
       required_fields,
-      autofill_field_formatter::CreateAutofillMappings(*profile_,
-                                                       /* locale = */ "en-US"),
+      field_formatter::CreateAutofillMappings(*profile_,
+                                              /* locale = */ "en-US"),
       delegate_);
 
   fallback_handler_->CheckAndFallbackRequiredFields(

components/autofill_assistant/browser/actions/use_credit_card_action.cc

@@ -11,6 +11,7 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/optional.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
@@ -20,8 +21,8 @@
 #include "components/autofill_assistant/browser/actions/action_delegate.h"
 #include "components/autofill_assistant/browser/actions/fallback_handler/required_field.h"
 #include "components/autofill_assistant/browser/actions/fallback_handler/required_fields_fallback_handler.h"
-#include "components/autofill_assistant/browser/autofill_field_formatter.h"
 #include "components/autofill_assistant/browser/client_status.h"
+#include "components/autofill_assistant/browser/field_formatter.h"
 #include "components/autofill_assistant/browser/user_model.h"
 
 namespace autofill_assistant {
@@ -150,14 +151,16 @@ void UseCreditCardAction::OnGetFullCard(
     required_fields.emplace_back(required_field);
   }
 
-  std::map<int, std::string> fallback_values =
-      autofill_field_formatter::CreateAutofillMappings(*card,
-                                                       /* locale = */ "en-US");
+  std::map<std::string, std::string> fallback_values =
+      field_formatter::CreateAutofillMappings(*card,
+                                              /* locale = */ "en-US");
   fallback_values.emplace(
-      static_cast<int>(AutofillFormatProto::CREDIT_CARD_VERIFICATION_CODE),
+      base::NumberToString(
+          static_cast<int>(AutofillFormatProto::CREDIT_CARD_VERIFICATION_CODE)),
       base::UTF16ToUTF8(cvc));
   fallback_values.emplace(
-      (int)AutofillFormatProto::CREDIT_CARD_RAW_NUMBER,
+      base::NumberToString(
+          static_cast<int>(AutofillFormatProto::CREDIT_CARD_RAW_NUMBER)),
       base::UTF16ToUTF8(card->GetRawInfo(autofill::CREDIT_CARD_NUMBER)));
 
   DCHECK(fallback_handler_ == nullptr);

components/autofill_assistant/browser/basic_interactions.cc

@@ -9,7 +9,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autofill_data_util.h"
-#include "components/autofill_assistant/browser/autofill_field_formatter.h"
+#include "components/autofill_assistant/browser/field_formatter.h"
 #include "components/autofill_assistant/browser/script_executor_delegate.h"
 #include "components/autofill_assistant/browser/trigger_context.h"
 #include "components/autofill_assistant/browser/user_model.h"
@@ -167,9 +167,9 @@ bool ValueToString(UserModel* user_model,
                    << ": credit card not found";
           return false;
         }
-        auto formatted_string = autofill_field_formatter::FormatString(
+        auto formatted_string = field_formatter::FormatAutofillString(
             proto.autofill_format().pattern(),
-            autofill_field_formatter::CreateAutofillMappings(
+            field_formatter::CreateAutofillMappings(
                 *credit_card, proto.autofill_format().locale()));
         if (!formatted_string.has_value()) {
           DVLOG(2) << "Error evaluating " << __func__
@@ -191,9 +191,9 @@ bool ValueToString(UserModel* user_model,
           DVLOG(2) << "Error evaluating " << __func__ << ": profile not found";
           return false;
         }
-        auto formatted_string = autofill_field_formatter::FormatString(
+        auto formatted_string = field_formatter::FormatAutofillString(
             proto.autofill_format().pattern(),
-            autofill_field_formatter::CreateAutofillMappings(
+            field_formatter::CreateAutofillMappings(
                 *profile, proto.autofill_format().locale()));
         if (!formatted_string.has_value()) {
           DVLOG(2) << "Error evaluating " << __func__

components/autofill_assistant/browser/autofill_field_formatter.cc → components/autofill_assistant/browser/field_formatter.cc

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/autofill_assistant/browser/autofill_field_formatter.h"
+#include "components/autofill_assistant/browser/field_formatter.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autofill_data_util.h"
@@ -13,28 +13,28 @@
 #include "third_party/re2/src/re2/stringpiece.h"
 
 namespace {
-// Regex to find placeholders of the form ${N}, where N is an integer (possibly
-// negative).
-const char kPlaceholderExtractor[] = R"re(\$\{(-?\d+)\})re";
+// Regex to find placeholders of the form ${key}, where key is an arbitrary
+// string that does not contain curly braces.
+const char kPlaceholderExtractor[] = R"re(\$\{([^{}]+)\})re";
 
 base::Optional<std::string> GetFieldValue(
-    const std::map<int, std::string>& mappings,
-    int i) {
-  auto it = mappings.find(i);
+    const std::map<std::string, std::string>& mappings,
+    const std::string& key) {
+  auto it = mappings.find(key);
   if (it == mappings.end()) {
     return base::nullopt;
   }
   return it->second;
 }
 
-std::map<int, std::string> CreateFormGroupMappings(
+std::map<std::string, std::string> CreateFormGroupMappings(
     const autofill::FormGroup& form_group,
     const std::string& locale) {
-  std::map<int, std::string> mappings;
+  std::map<std::string, std::string> mappings;
   autofill::ServerFieldTypeSet available_fields;
   form_group.GetNonEmptyTypes(locale, &available_fields);
   for (const auto& field : available_fields) {
-    mappings.emplace(static_cast<int>(field),
+    mappings.emplace(base::NumberToString(static_cast<int>(field)),
                      base::UTF16ToUTF8(form_group.GetInfo(
                          autofill::AutofillType(field), locale)));
   }
@@ -44,11 +44,11 @@ std::map<int, std::string> CreateFormGroupMappings(
 }  // namespace
 
 namespace autofill_assistant {
-namespace autofill_field_formatter {
+namespace field_formatter {
 
-base::Optional<std::string> FormatString(
+base::Optional<std::string> FormatAutofillString(
     const std::string& pattern,
-    const std::map<int, std::string> mappings) {
+    const std::map<std::string, std::string>& mappings) {
   if (pattern.empty()) {
     return std::string();
   }
@@ -56,15 +56,26 @@ base::Optional<std::string> FormatString(
   // Special case: if the input is a single number, interpret as ${N}.
   int field_type;
   if (base::StringToInt(pattern, &field_type)) {
-    return GetFieldValue(mappings, field_type);
+    return GetFieldValue(mappings, pattern);
+  }
+
+  return FormatString(pattern, mappings);
+}
+
+base::Optional<std::string> FormatString(
+    const std::string& pattern,
+    const std::map<std::string, std::string>& mappings) {
+  if (pattern.empty()) {
+    return std::string();
   }
 
+  std::string key;
   std::string out = pattern;
   re2::StringPiece input(pattern);
-  while (re2::RE2::FindAndConsume(&input, kPlaceholderExtractor, &field_type)) {
-    auto rewrite_value = GetFieldValue(mappings, field_type);
+  while (re2::RE2::FindAndConsume(&input, kPlaceholderExtractor, &key)) {
+    auto rewrite_value = GetFieldValue(mappings, key);
     if (!rewrite_value.has_value()) {
-      VLOG(2) << "No value for " << field_type << " in " << pattern;
+      VLOG(2) << "No value for " << key << " in " << pattern;
       return base::nullopt;
     }
 
@@ -76,14 +87,15 @@ base::Optional<std::string> FormatString(
 }
 
 template <>
-std::map<int, std::string> CreateAutofillMappings<autofill::AutofillProfile>(
+std::map<std::string, std::string>
+CreateAutofillMappings<autofill::AutofillProfile>(
     const autofill::AutofillProfile& profile,
     const std::string& locale) {
   return CreateFormGroupMappings(profile, locale);
 }
 
 template <>
-std::map<int, std::string> CreateAutofillMappings<autofill::CreditCard>(
+std::map<std::string, std::string> CreateAutofillMappings<autofill::CreditCard>(
     const autofill::CreditCard& credit_card,
     const std::string& locale) {
   auto mappings = CreateFormGroupMappings(credit_card, locale);
@@ -92,24 +104,24 @@ std::map<int, std::string> CreateAutofillMappings<autofill::CreditCard>(
       autofill::data_util::GetPaymentRequestData(credit_card.network())
           .basic_card_issuer_network);
   if (!network.empty()) {
-    mappings[static_cast<int>(AutofillFormatProto::CREDIT_CARD_NETWORK)] =
-        network;
+    mappings[base::NumberToString(
+        static_cast<int>(AutofillFormatProto::CREDIT_CARD_NETWORK))] = network;
   }
   auto network_for_display = base::UTF16ToUTF8(credit_card.NetworkForDisplay());
   if (!network_for_display.empty()) {
-    mappings[static_cast<int>(
-        AutofillFormatProto::CREDIT_CARD_NETWORK_FOR_DISPLAY)] =
+    mappings[base::NumberToString(static_cast<int>(
+        AutofillFormatProto::CREDIT_CARD_NETWORK_FOR_DISPLAY))] =
         network_for_display;
   }
   auto last_four_digits = base::UTF16ToUTF8(credit_card.LastFourDigits());
   if (!last_four_digits.empty()) {
-    mappings[static_cast<int>(
-        AutofillFormatProto::CREDIT_CARD_NUMBER_LAST_FOUR_DIGITS)] =
+    mappings[base::NumberToString(static_cast<int>(
+        AutofillFormatProto::CREDIT_CARD_NUMBER_LAST_FOUR_DIGITS))] =
         last_four_digits;
   }
 
   return mappings;
 }
 
-}  // namespace autofill_field_formatter
+}  // namespace field_formatter
 }  // namespace autofill_assistant

components/autofill_assistant/browser/autofill_field_formatter.h → components/autofill_assistant/browser/field_formatter.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_AUTOFILL_FIELD_FORMATTER_H_
-#define COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_AUTOFILL_FIELD_FORMATTER_H_
+#ifndef COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_FIELD_FORMATTER_H_
+#define COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_FIELD_FORMATTER_H_
 
 #include <map>
 #include <string>
@@ -12,26 +12,33 @@
 #include "components/autofill/core/browser/data_model/credit_card.h"
 
 namespace autofill_assistant {
-namespace autofill_field_formatter {
+namespace field_formatter {
 
-// Replaces all placeholder occurrences of the form ${N} in |pattern| with the
-// corresponding value in |mappings|. Returns the result or nullopt if any
-// of the requested fields was not available. As a special case, input patterns
+// Replaces all placeholder occurrences of the form ${key} in |input| with the
+// corresponding value in |mappings|, where |key| is an arbitrary string that
+// does not contain curly braces. Fails if any of the found placeholders is not
+// in |mappings|.
+base::Optional<std::string> FormatString(
+    const std::string& input,
+    const std::map<std::string, std::string>& mappings);
+
+// Same as |FormatString|, but also supports a special case: input patterns
 // containing a single integer are also allowed and implicitly interpreted as
 // ${N}.
-base::Optional<std::string> FormatString(
+base::Optional<std::string> FormatAutofillString(
     const std::string& pattern,
-    const std::map<int, std::string> mappings);
+    const std::map<std::string, std::string>& mappings);
 
 // Creates a lookup map for all non-empty autofill and custom
 // AutofillFormatProto::AutofillAssistantCustomField field types in
 // |autofill_data_model|.
 // |locale| should be a locale string such as "en-US".
 template <typename T>
-std::map<int, std::string> CreateAutofillMappings(const T& autofill_data_model,
-                                                  const std::string& locale);
+std::map<std::string, std::string> CreateAutofillMappings(
+    const T& autofill_data_model,
+    const std::string& locale);
 
-}  // namespace autofill_field_formatter
+}  // namespace field_formatter
 }  // namespace autofill_assistant
 
-#endif  // COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_AUTOFILL_FIELD_FORMATTER_H_
+#endif  // COMPONENTS_AUTOFILL_ASSISTANT_BROWSER_FIELD_FORMATTER_H_