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-rw-r--r--js/loader/ImportMap.cpp697
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diff --git a/js/loader/ImportMap.cpp b/js/loader/ImportMap.cpp
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+++ b/js/loader/ImportMap.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImportMap.h"
+
+#include "js/Array.h" // IsArrayObject
+#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_*
+#include "js/JSON.h" // JS_ParseJSON
+#include "LoadedScript.h"
+#include "ModuleLoaderBase.h" // ScriptLoaderInterface
+#include "nsContentUtils.h"
+#include "nsIScriptElement.h"
+#include "nsIScriptError.h"
+#include "nsJSUtils.h" // nsAutoJSString
+#include "nsNetUtil.h" // NS_NewURI
+#include "ScriptLoadRequest.h"
+
+using JS::SourceText;
+using mozilla::Err;
+using mozilla::LazyLogModule;
+using mozilla::MakeUnique;
+using mozilla::UniquePtr;
+using mozilla::WrapNotNull;
+
+namespace JS::loader {
+
+LazyLogModule ImportMap::gImportMapLog("ImportMap");
+
+#undef LOG
+#define LOG(args) \
+ MOZ_LOG(ImportMap::gImportMapLog, mozilla::LogLevel::Debug, args)
+
+#define LOG_ENABLED() \
+ MOZ_LOG_TEST(ImportMap::gImportMapLog, mozilla::LogLevel::Debug)
+
+void ReportWarningHelper::Report(const char* aMessageName,
+ const nsTArray<nsString>& aParams) const {
+ mLoader->ReportWarningToConsole(mRequest, aMessageName, aParams);
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#resolving-a-url-like-module-specifier
+static ResolveResult ResolveURLLikeModuleSpecifier(const nsAString& aSpecifier,
+ nsIURI* aBaseURL) {
+ nsCOMPtr<nsIURI> uri;
+ nsresult rv;
+
+ // Step 1. If specifier starts with "/", "./", or "../", then:
+ if (StringBeginsWith(aSpecifier, u"/"_ns) ||
+ StringBeginsWith(aSpecifier, u"./"_ns) ||
+ StringBeginsWith(aSpecifier, u"../"_ns)) {
+ // Step 1.1. Let url be the result of parsing specifier with baseURL as the
+ // base URL.
+ rv = NS_NewURI(getter_AddRefs(uri), aSpecifier, nullptr, aBaseURL);
+ // Step 1.2. If url is failure, then return null.
+ if (NS_FAILED(rv)) {
+ return Err(ResolveError::Failure);
+ }
+
+ // Step 1.3. Return url.
+ return WrapNotNull(uri);
+ }
+
+ // Step 2. Let url be the result of parsing specifier (with no base URL).
+ rv = NS_NewURI(getter_AddRefs(uri), aSpecifier);
+ // Step 3. If url is failure, then return null.
+ if (NS_FAILED(rv)) {
+ return Err(ResolveError::FailureMayBeBare);
+ }
+
+ // Step 4. Return url.
+ return WrapNotNull(uri);
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#normalizing-a-specifier-key
+static void NormalizeSpecifierKey(const nsAString& aSpecifierKey,
+ nsIURI* aBaseURL,
+ const ReportWarningHelper& aWarning,
+ nsAString& aRetVal) {
+ // Step 1. If specifierKey is the empty string, then:
+ if (aSpecifierKey.IsEmpty()) {
+ // Step 1.1. Report a warning to the console that specifier keys cannot be
+ // the empty string.
+ aWarning.Report("ImportMapEmptySpecifierKeys");
+
+ // Step 1.2. Return null.
+ aRetVal = EmptyString();
+ return;
+ }
+
+ // Step 2. Let url be the result of resolving a URL-like module specifier,
+ // given specifierKey and baseURL.
+ auto parseResult = ResolveURLLikeModuleSpecifier(aSpecifierKey, aBaseURL);
+
+ // Step 3. If url is not null, then return the serialization of url.
+ if (parseResult.isOk()) {
+ nsCOMPtr<nsIURI> url = parseResult.unwrap();
+ aRetVal = NS_ConvertUTF8toUTF16(url->GetSpecOrDefault());
+ return;
+ }
+
+ // Step 4. Return specifierKey.
+ aRetVal = aSpecifierKey;
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#sorting-and-normalizing-a-module-specifier-map
+static UniquePtr<SpecifierMap> SortAndNormalizeSpecifierMap(
+ JSContext* aCx, JS::HandleObject aOriginalMap, nsIURI* aBaseURL,
+ const ReportWarningHelper& aWarning) {
+ // Step 1. Let normalized be an empty ordered map.
+ UniquePtr<SpecifierMap> normalized = MakeUnique<SpecifierMap>();
+
+ JS::Rooted<JS::IdVector> specifierKeys(aCx, JS::IdVector(aCx));
+ if (!JS_Enumerate(aCx, aOriginalMap, &specifierKeys)) {
+ return nullptr;
+ }
+
+ // Step 2. For each specifierKey → value of originalMap,
+ for (size_t i = 0; i < specifierKeys.length(); i++) {
+ const JS::RootedId specifierId(aCx, specifierKeys[i]);
+ nsAutoJSString specifierKey;
+ NS_ENSURE_TRUE(specifierKey.init(aCx, specifierId), nullptr);
+
+ // Step 2.1. Let normalizedSpecifierKey be the result of normalizing a
+ // specifier key given specifierKey and baseURL.
+ nsString normalizedSpecifierKey;
+ NormalizeSpecifierKey(specifierKey, aBaseURL, aWarning,
+ normalizedSpecifierKey);
+
+ // Step 2.2. If normalizedSpecifierKey is null, then continue.
+ if (normalizedSpecifierKey.IsEmpty()) {
+ continue;
+ }
+
+ JS::RootedValue idVal(aCx);
+ NS_ENSURE_TRUE(JS_GetPropertyById(aCx, aOriginalMap, specifierId, &idVal),
+ nullptr);
+ // Step 2.3. If value is not a string, then:
+ if (!idVal.isString()) {
+ // Step 2.3.1. The user agent may report a warning to the console
+ // indicating that addresses need to be strings.
+ aWarning.Report("ImportMapAddressesNotStrings");
+
+ // Step 2.3.2. Set normalized[normalizedSpecifierKey] to null.
+ normalized->insert_or_assign(normalizedSpecifierKey, nullptr);
+
+ // Step 2.3.3. Continue.
+ continue;
+ }
+
+ nsAutoJSString value;
+ NS_ENSURE_TRUE(value.init(aCx, idVal), nullptr);
+
+ // Step 2.4. Let addressURL be the result of resolving a URL-like module
+ // specifier given value and baseURL.
+ auto parseResult = ResolveURLLikeModuleSpecifier(value, aBaseURL);
+
+ // Step 2.5. If addressURL is null, then:
+ if (parseResult.isErr()) {
+ // Step 2.5.1. The user agent may report a warning to the console
+ // indicating that the address was invalid.
+ AutoTArray<nsString, 1> params;
+ params.AppendElement(value);
+ aWarning.Report("ImportMapInvalidAddress", params);
+
+ // Step 2.5.2. Set normalized[normalizedSpecifierKey] to null.
+ normalized->insert_or_assign(normalizedSpecifierKey, nullptr);
+
+ // Step 2.5.3. Continue.
+ continue;
+ }
+
+ nsCOMPtr<nsIURI> addressURL = parseResult.unwrap();
+ nsCString address = addressURL->GetSpecOrDefault();
+ // Step 2.6. If specifierKey ends with U+002F (/), and the serialization
+ // of addressURL does not end with U+002F (/), then:
+ if (StringEndsWith(specifierKey, u"/"_ns) &&
+ !StringEndsWith(address, "/"_ns)) {
+ // Step 2.6.1. The user agent may report a warning to the console
+ // indicating that an invalid address was given for the specifier key
+ // specifierKey; since specifierKey ends with a slash, the address needs
+ // to as well.
+ AutoTArray<nsString, 2> params;
+ params.AppendElement(specifierKey);
+ params.AppendElement(NS_ConvertUTF8toUTF16(address));
+ aWarning.Report("ImportMapAddressNotEndsWithSlash", params);
+
+ // Step 2.6.2. Set normalized[normalizedSpecifierKey] to null.
+ normalized->insert_or_assign(normalizedSpecifierKey, nullptr);
+
+ // Step 2.6.3. Continue.
+ continue;
+ }
+
+ LOG(("ImportMap::SortAndNormalizeSpecifierMap {%s, %s}",
+ NS_ConvertUTF16toUTF8(normalizedSpecifierKey).get(),
+ addressURL->GetSpecOrDefault().get()));
+
+ // Step 2.7. Set normalized[normalizedSpecifierKey] to addressURL.
+ normalized->insert_or_assign(normalizedSpecifierKey, addressURL);
+ }
+
+ // Step 3: Return the result of sorting normalized, with an entry a being
+ // less than an entry b if b’s key is code unit less than a’s key.
+ //
+ // Impl note: The sorting is done when inserting the entry.
+ return normalized;
+}
+
+// Check if it's a map defined in
+// https://infra.spec.whatwg.org/#ordered-map
+//
+// If it is, *aIsMap will be set to true.
+static bool IsMapObject(JSContext* aCx, JS::HandleValue aMapVal, bool* aIsMap) {
+ MOZ_ASSERT(aIsMap);
+
+ *aIsMap = false;
+ if (!aMapVal.isObject()) {
+ return true;
+ }
+
+ bool isArray;
+ if (!IsArrayObject(aCx, aMapVal, &isArray)) {
+ return false;
+ }
+
+ *aIsMap = !isArray;
+ return true;
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#sorting-and-normalizing-scopes
+static UniquePtr<ScopeMap> SortAndNormalizeScopes(
+ JSContext* aCx, JS::HandleObject aOriginalMap, nsIURI* aBaseURL,
+ const ReportWarningHelper& aWarning) {
+ JS::Rooted<JS::IdVector> scopeKeys(aCx, JS::IdVector(aCx));
+ if (!JS_Enumerate(aCx, aOriginalMap, &scopeKeys)) {
+ return nullptr;
+ }
+
+ // Step 1. Let normalized be an empty map.
+ UniquePtr<ScopeMap> normalized = MakeUnique<ScopeMap>();
+
+ // Step 2. For each scopePrefix → potentialSpecifierMap of originalMap,
+ for (size_t i = 0; i < scopeKeys.length(); i++) {
+ const JS::RootedId scopeKey(aCx, scopeKeys[i]);
+ nsAutoJSString scopePrefix;
+ NS_ENSURE_TRUE(scopePrefix.init(aCx, scopeKey), nullptr);
+
+ // Step 2.1. If potentialSpecifierMap is not an ordered map, then throw a
+ // TypeError indicating that the value of the scope with prefix scopePrefix
+ // needs to be a JSON object.
+ JS::RootedValue mapVal(aCx);
+ NS_ENSURE_TRUE(JS_GetPropertyById(aCx, aOriginalMap, scopeKey, &mapVal),
+ nullptr);
+
+ bool isMap;
+ if (!IsMapObject(aCx, mapVal, &isMap)) {
+ return nullptr;
+ }
+ if (!isMap) {
+ const char16_t* scope = scopePrefix.get();
+ JS_ReportErrorNumberUC(aCx, js::GetErrorMessage, nullptr,
+ JSMSG_IMPORT_MAPS_SCOPE_VALUE_NOT_A_MAP, scope);
+ return nullptr;
+ }
+
+ // Step 2.2. Let scopePrefixURL be the result of URL parsing scopePrefix
+ // with baseURL.
+ nsCOMPtr<nsIURI> scopePrefixURL;
+ nsresult rv = NS_NewURI(getter_AddRefs(scopePrefixURL), scopePrefix,
+ nullptr, aBaseURL);
+
+ // Step 2.3. If scopePrefixURL is failure, then:
+ if (NS_FAILED(rv)) {
+ // Step 2.3.1. The user agent may report a warning to the console that
+ // the scope prefix URL was not parseable.
+ AutoTArray<nsString, 1> params;
+ params.AppendElement(scopePrefix);
+ aWarning.Report("ImportMapScopePrefixNotParseable", params);
+
+ // Step 2.3.2. Continue.
+ continue;
+ }
+
+ // Step 2.4. Let normalizedScopePrefix be the serialization of
+ // scopePrefixURL.
+ nsCString normalizedScopePrefix = scopePrefixURL->GetSpecOrDefault();
+
+ // Step 2.5. Set normalized[normalizedScopePrefix] to the result of sorting
+ // and normalizing a specifier map given potentialSpecifierMap and baseURL.
+ JS::RootedObject potentialSpecifierMap(aCx, &mapVal.toObject());
+ UniquePtr<SpecifierMap> specifierMap = SortAndNormalizeSpecifierMap(
+ aCx, potentialSpecifierMap, aBaseURL, aWarning);
+ if (!specifierMap) {
+ return nullptr;
+ }
+
+ normalized->insert_or_assign(normalizedScopePrefix,
+ std::move(specifierMap));
+ }
+
+ // Step 3. Return the result of sorting in descending order normalized, with
+ // an entry a being less than an entry b if a's key is code unit less than b's
+ // key.
+ //
+ // Impl note: The sorting is done when inserting the entry.
+ return normalized;
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#parse-an-import-map-string
+// static
+UniquePtr<ImportMap> ImportMap::ParseString(
+ JSContext* aCx, SourceText<char16_t>& aInput, nsIURI* aBaseURL,
+ const ReportWarningHelper& aWarning) {
+ // Step 1. Let parsed be the result of parsing JSON into Infra values given
+ // input.
+ JS::Rooted<JS::Value> parsedVal(aCx);
+ if (!JS_ParseJSON(aCx, aInput.get(), aInput.length(), &parsedVal)) {
+ NS_WARNING("Parsing Import map string failed");
+
+ // If JS_ParseJSON fails we check if it throws a SyntaxError.
+ // If so we update the error message from JSON parser to make it more clear
+ // that the parsing of import map has failed.
+ MOZ_ASSERT(JS_IsExceptionPending(aCx));
+ JS::Rooted<JS::Value> exn(aCx);
+ if (!JS_GetPendingException(aCx, &exn)) {
+ return nullptr;
+ }
+ MOZ_ASSERT(exn.isObject());
+ JS::Rooted<JSObject*> obj(aCx, &exn.toObject());
+ JSErrorReport* err = JS_ErrorFromException(aCx, obj);
+ if (err->exnType == JSEXN_SYNTAXERR) {
+ JS_ClearPendingException(aCx);
+ JS_ReportErrorNumberASCII(aCx, js::GetErrorMessage, nullptr,
+ JSMSG_IMPORT_MAPS_PARSE_FAILED,
+ err->message().c_str());
+ }
+
+ return nullptr;
+ }
+
+ // Step 2. If parsed is not an ordered map, then throw a TypeError indicating
+ // that the top-level value needs to be a JSON object.
+ bool isMap;
+ if (!IsMapObject(aCx, parsedVal, &isMap)) {
+ return nullptr;
+ }
+ if (!isMap) {
+ JS_ReportErrorNumberASCII(aCx, js::GetErrorMessage, nullptr,
+ JSMSG_IMPORT_MAPS_NOT_A_MAP);
+ return nullptr;
+ }
+
+ JS::RootedObject parsedObj(aCx, &parsedVal.toObject());
+ JS::RootedValue importsVal(aCx);
+ if (!JS_GetProperty(aCx, parsedObj, "imports", &importsVal)) {
+ return nullptr;
+ }
+
+ // Step 3. Let sortedAndNormalizedImports be an empty ordered map.
+ //
+ // Impl note: If parsed["imports"] doesn't exist, we will allocate
+ // sortedAndNormalizedImports to an empty map in Step 8 below.
+ UniquePtr<SpecifierMap> sortedAndNormalizedImports = nullptr;
+
+ // Step 4. If parsed["imports"] exists, then:
+ if (!importsVal.isUndefined()) {
+ // Step 4.1. If parsed["imports"] is not an ordered map, then throw a
+ // TypeError indicating that the "imports" top-level key needs to be a JSON
+ // object.
+ bool isMap;
+ if (!IsMapObject(aCx, importsVal, &isMap)) {
+ return nullptr;
+ }
+ if (!isMap) {
+ JS_ReportErrorNumberASCII(aCx, js::GetErrorMessage, nullptr,
+ JSMSG_IMPORT_MAPS_IMPORTS_NOT_A_MAP);
+ return nullptr;
+ }
+
+ // Step 4.2. Set sortedAndNormalizedImports to the result of sorting and
+ // normalizing a module specifier map given parsed["imports"] and baseURL.
+ JS::RootedObject importsObj(aCx, &importsVal.toObject());
+ sortedAndNormalizedImports =
+ SortAndNormalizeSpecifierMap(aCx, importsObj, aBaseURL, aWarning);
+ if (!sortedAndNormalizedImports) {
+ return nullptr;
+ }
+ }
+
+ JS::RootedValue scopesVal(aCx);
+ if (!JS_GetProperty(aCx, parsedObj, "scopes", &scopesVal)) {
+ return nullptr;
+ }
+
+ // Step 5. Let sortedAndNormalizedScopes be an empty ordered map.
+ //
+ // Impl note: If parsed["scopes"] doesn't exist, we will allocate
+ // sortedAndNormalizedScopes to an empty map in Step 8 below.
+ UniquePtr<ScopeMap> sortedAndNormalizedScopes = nullptr;
+
+ // Step 6. If parsed["scopes"] exists, then:
+ if (!scopesVal.isUndefined()) {
+ // Step 6.1. If parsed["scopes"] is not an ordered map, then throw a
+ // TypeError indicating that the "scopes" top-level key needs to be a JSON
+ // object.
+ bool isMap;
+ if (!IsMapObject(aCx, scopesVal, &isMap)) {
+ return nullptr;
+ }
+ if (!isMap) {
+ JS_ReportErrorNumberASCII(aCx, js::GetErrorMessage, nullptr,
+ JSMSG_IMPORT_MAPS_SCOPES_NOT_A_MAP);
+ return nullptr;
+ }
+
+ // Step 6.2. Set sortedAndNormalizedScopes to the result of sorting and
+ // normalizing scopes given parsed["scopes"] and baseURL.
+ JS::RootedObject scopesObj(aCx, &scopesVal.toObject());
+ sortedAndNormalizedScopes =
+ SortAndNormalizeScopes(aCx, scopesObj, aBaseURL, aWarning);
+ if (!sortedAndNormalizedScopes) {
+ return nullptr;
+ }
+ }
+
+ // Step 7. If parsed’s keys contains any items besides "imports" or
+ // "scopes", then the user agent should report a warning to the console
+ // indicating that an invalid top-level key was present in the import map.
+ JS::Rooted<JS::IdVector> keys(aCx, JS::IdVector(aCx));
+ if (!JS_Enumerate(aCx, parsedObj, &keys)) {
+ return nullptr;
+ }
+
+ for (size_t i = 0; i < keys.length(); i++) {
+ const JS::RootedId key(aCx, keys[i]);
+ nsAutoJSString val;
+ NS_ENSURE_TRUE(val.init(aCx, key), nullptr);
+ if (val.EqualsLiteral("imports") || val.EqualsLiteral("scopes")) {
+ continue;
+ }
+
+ AutoTArray<nsString, 1> params;
+ params.AppendElement(val);
+ aWarning.Report("ImportMapInvalidTopLevelKey", params);
+ }
+
+ // Impl note: Create empty maps for sortedAndNormalizedImports and
+ // sortedAndNormalizedImports if they aren't allocated.
+ if (!sortedAndNormalizedImports) {
+ sortedAndNormalizedImports = MakeUnique<SpecifierMap>();
+ }
+ if (!sortedAndNormalizedScopes) {
+ sortedAndNormalizedScopes = MakeUnique<ScopeMap>();
+ }
+
+ // Step 8. Return an import map whose imports are
+ // sortedAndNormalizedImports and whose scopes scopes are
+ // sortedAndNormalizedScopes.
+ return MakeUnique<ImportMap>(std::move(sortedAndNormalizedImports),
+ std::move(sortedAndNormalizedScopes));
+}
+
+// https://url.spec.whatwg.org/#is-special
+static bool IsSpecialScheme(nsIURI* aURI) {
+ nsAutoCString scheme;
+ aURI->GetScheme(scheme);
+ return scheme.EqualsLiteral("ftp") || scheme.EqualsLiteral("file") ||
+ scheme.EqualsLiteral("http") || scheme.EqualsLiteral("https") ||
+ scheme.EqualsLiteral("ws") || scheme.EqualsLiteral("wss");
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#resolving-an-imports-match
+static mozilla::Result<nsCOMPtr<nsIURI>, ResolveError> ResolveImportsMatch(
+ nsString& aNormalizedSpecifier, nsIURI* aAsURL,
+ const SpecifierMap* aSpecifierMap) {
+ // Step 1. For each specifierKey → resolutionResult of specifierMap,
+ for (auto&& [specifierKey, resolutionResult] : *aSpecifierMap) {
+ nsAutoString specifier{aNormalizedSpecifier};
+ nsCString asURL = aAsURL ? aAsURL->GetSpecOrDefault() : EmptyCString();
+
+ // Step 1.1. If specifierKey is normalizedSpecifier, then:
+ if (specifierKey.Equals(aNormalizedSpecifier)) {
+ // Step 1.1.1. If resolutionResult is null, then throw a TypeError
+ // indicating that resolution of specifierKey was blocked by a null entry.
+ // This will terminate the entire resolve a module specifier algorithm,
+ // without any further fallbacks.
+ if (!resolutionResult) {
+ LOG(
+ ("ImportMap::ResolveImportsMatch normalizedSpecifier: %s, "
+ "specifierKey: %s, but resolution is null.",
+ NS_ConvertUTF16toUTF8(aNormalizedSpecifier).get(),
+ NS_ConvertUTF16toUTF8(specifierKey).get()));
+ return Err(ResolveError::BlockedByNullEntry);
+ }
+
+ // Step 1.1.2. Assert: resolutionResult is a URL.
+ MOZ_ASSERT(resolutionResult);
+
+ // Step 1.1.3. Return resolutionResult.
+ return resolutionResult;
+ }
+
+ // Step 1.2. If all of the following are true:
+ // specifierKey ends with U+002F (/),
+ // specifierKey is a code unit prefix of normalizedSpecifier, and
+ // either asURL is null, or asURL is special
+ if (StringEndsWith(specifierKey, u"/"_ns) &&
+ StringBeginsWith(aNormalizedSpecifier, specifierKey) &&
+ (!aAsURL || IsSpecialScheme(aAsURL))) {
+ // Step 1.2.1. If resolutionResult is null, then throw a TypeError
+ // indicating that resolution of specifierKey was blocked by a null entry.
+ // This will terminate the entire resolve a module specifier algorithm,
+ // without any further fallbacks.
+ if (!resolutionResult) {
+ LOG(
+ ("ImportMap::ResolveImportsMatch normalizedSpecifier: %s, "
+ "specifierKey: %s, but resolution is null.",
+ NS_ConvertUTF16toUTF8(aNormalizedSpecifier).get(),
+ NS_ConvertUTF16toUTF8(specifierKey).get()));
+ return Err(ResolveError::BlockedByNullEntry);
+ }
+
+ // Step 1.2.2. Assert: resolutionResult is a URL.
+ MOZ_ASSERT(resolutionResult);
+
+ // Step 1.2.3. Let afterPrefix be the portion of normalizedSpecifier after
+ // the initial specifierKey prefix.
+ nsAutoString afterPrefix(
+ Substring(aNormalizedSpecifier, specifierKey.Length()));
+
+ // Step 1.2.4. Assert: resolutionResult, serialized, ends with U+002F (/),
+ // as enforced during parsing
+ MOZ_ASSERT(StringEndsWith(resolutionResult->GetSpecOrDefault(), "/"_ns));
+
+ // Step 1.2.5. Let url be the result of URL parsing afterPrefix with
+ // resolutionResult.
+ nsCOMPtr<nsIURI> url;
+ nsresult rv = NS_NewURI(getter_AddRefs(url), afterPrefix, nullptr,
+ resolutionResult);
+
+ // Step 1.2.6. If url is failure, then throw a TypeError indicating that
+ // resolution of normalizedSpecifier was blocked since the afterPrefix
+ // portion could not be URL-parsed relative to the resolutionResult mapped
+ // to by the specifierKey prefix.
+ //
+ // This will terminate the entire resolve a module specifier algorithm,
+ // without any further fallbacks.
+ if (NS_FAILED(rv)) {
+ LOG(
+ ("ImportMap::ResolveImportsMatch normalizedSpecifier: %s, "
+ "specifierKey: %s, resolutionResult: %s, afterPrefix: %s, "
+ "but URL is not parsable.",
+ NS_ConvertUTF16toUTF8(aNormalizedSpecifier).get(),
+ NS_ConvertUTF16toUTF8(specifierKey).get(),
+ resolutionResult->GetSpecOrDefault().get(),
+ NS_ConvertUTF16toUTF8(afterPrefix).get()));
+ return Err(ResolveError::BlockedByAfterPrefix);
+ }
+
+ // Step 1.2.7. Assert: url is a URL.
+ MOZ_ASSERT(url);
+
+ // Step 1.2.8. If the serialization of resolutionResult is not a code unit
+ // prefix of the serialization of url, then throw a TypeError indicating
+ // that resolution of normalizedSpecifier was blocked due to it
+ // backtracking above its prefix specifierKey.
+ //
+ // This will terminate the entire resolve a module specifier algorithm,
+ // without any further fallbacks.
+ if (!StringBeginsWith(url->GetSpecOrDefault(),
+ resolutionResult->GetSpecOrDefault())) {
+ LOG(
+ ("ImportMap::ResolveImportsMatch normalizedSpecifier: %s, "
+ "specifierKey: %s, "
+ "url %s does not start with resolutionResult %s.",
+ NS_ConvertUTF16toUTF8(aNormalizedSpecifier).get(),
+ NS_ConvertUTF16toUTF8(specifierKey).get(),
+ url->GetSpecOrDefault().get(),
+ resolutionResult->GetSpecOrDefault().get()));
+ return Err(ResolveError::BlockedByBacktrackingPrefix);
+ }
+
+ // Step 1.2.9. Return url.
+ return std::move(url);
+ }
+ }
+
+ // Step 2. Return null.
+ return nsCOMPtr<nsIURI>(nullptr);
+}
+
+// https://html.spec.whatwg.org/multipage/webappapis.html#resolve-a-module-specifier
+// static
+ResolveResult ImportMap::ResolveModuleSpecifier(ImportMap* aImportMap,
+ ScriptLoaderInterface* aLoader,
+ LoadedScript* aScript,
+ const nsAString& aSpecifier) {
+ LOG(("ImportMap::ResolveModuleSpecifier specifier: %s",
+ NS_ConvertUTF16toUTF8(aSpecifier).get()));
+ nsCOMPtr<nsIURI> baseURL;
+ if (aScript && !aScript->IsEventScript()) {
+ baseURL = aScript->BaseURL();
+ } else {
+ baseURL = aLoader->GetBaseURI();
+ }
+
+ // Step 7. Let asURL be the result of resolving a URL-like module specifier
+ // given specifier and baseURL.
+ //
+ // Impl note: Step 6 is done below if aImportMap exists.
+ auto parseResult = ResolveURLLikeModuleSpecifier(aSpecifier, baseURL);
+ nsCOMPtr<nsIURI> asURL;
+ if (parseResult.isOk()) {
+ asURL = parseResult.unwrap();
+ }
+
+ if (aImportMap) {
+ // Step 6. Let baseURLString be baseURL, serialized.
+ nsCString baseURLString = baseURL->GetSpecOrDefault();
+
+ // Step 8. Let normalizedSpecifier be the serialization of asURL, if asURL
+ // is non-null; otherwise, specifier.
+ nsAutoString normalizedSpecifier =
+ asURL ? NS_ConvertUTF8toUTF16(asURL->GetSpecOrDefault())
+ : nsAutoString{aSpecifier};
+
+ // Step 9. For each scopePrefix → scopeImports of importMap’s scopes,
+ for (auto&& [scopePrefix, scopeImports] : *aImportMap->mScopes) {
+ // Step 9.1. If scopePrefix is baseURLString, or if scopePrefix ends with
+ // U+002F (/) and scopePrefix is a code unit prefix of baseURLString,
+ // then:
+ if (scopePrefix.Equals(baseURLString) ||
+ (StringEndsWith(scopePrefix, "/"_ns) &&
+ StringBeginsWith(baseURLString, scopePrefix))) {
+ // Step 9.1.1. Let scopeImportsMatch be the result of resolving an
+ // imports match given normalizedSpecifier, asURL, and scopeImports.
+ auto result =
+ ResolveImportsMatch(normalizedSpecifier, asURL, scopeImports.get());
+ if (result.isErr()) {
+ return result.propagateErr();
+ }
+
+ nsCOMPtr<nsIURI> scopeImportsMatch = result.unwrap();
+ // Step 9.1.2. If scopeImportsMatch is not null, then return
+ // scopeImportsMatch.
+ if (scopeImportsMatch) {
+ LOG((
+ "ImportMap::ResolveModuleSpecifier returns scopeImportsMatch: %s",
+ scopeImportsMatch->GetSpecOrDefault().get()));
+ return WrapNotNull(scopeImportsMatch);
+ }
+ }
+ }
+
+ // Step 10. Let topLevelImportsMatch be the result of resolving an imports
+ // match given normalizedSpecifier, asURL, and importMap’s imports.
+ auto result = ResolveImportsMatch(normalizedSpecifier, asURL,
+ aImportMap->mImports.get());
+ if (result.isErr()) {
+ return result.propagateErr();
+ }
+ nsCOMPtr<nsIURI> topLevelImportsMatch = result.unwrap();
+
+ // Step 11. If topLevelImportsMatch is not null, then return
+ // topLevelImportsMatch.
+ if (topLevelImportsMatch) {
+ LOG(("ImportMap::ResolveModuleSpecifier returns topLevelImportsMatch: %s",
+ topLevelImportsMatch->GetSpecOrDefault().get()));
+ return WrapNotNull(topLevelImportsMatch);
+ }
+ }
+
+ // Step 12. At this point, the specifier was able to be turned in to a URL,
+ // but it wasn’t remapped to anything by importMap. If asURL is not null, then
+ // return asURL.
+ if (asURL) {
+ LOG(("ImportMap::ResolveModuleSpecifier returns asURL: %s",
+ asURL->GetSpecOrDefault().get()));
+ return WrapNotNull(asURL);
+ }
+
+ // Step 13. Throw a TypeError indicating that specifier was a bare specifier,
+ // but was not remapped to anything by importMap.
+ if (parseResult.unwrapErr() != ResolveError::FailureMayBeBare) {
+ // We may have failed to parse a non-bare specifier for another reason.
+ return Err(ResolveError::Failure);
+ }
+
+ return Err(ResolveError::InvalidBareSpecifier);
+}
+
+#undef LOG
+#undef LOG_ENABLED
+} // namespace JS::loader