Split up state controller

src/background/stateControllerListeners.test.ts

@@ -18,20 +18,20 @@
 import { modComponentRefFactory } from "@/testUtils/factories/modComponentFactories";
 import {
   getState,
-  registerModVariables,
   setState,
-  TEST_resetState,
-} from "@/contentScript/stateController";
+  TEST_resetStateController,
+} from "@/contentScript/stateController/stateController";
 import { MergeStrategies, StateNamespaces } from "@/platform/state/stateTypes";
 import type { JSONSchema7Definition } from "json-schema";
 import {
   deleteSynchronizedModVariablesForMod,
   deleteSynchronizedModVariablesForTab,
 } from "@/background/stateControllerListeners";
 import { getThisFrame } from "webext-messenger";
+import { registerModVariables } from "@/contentScript/stateController/modVariablePolicyController";
 
 beforeEach(async () => {
-  await TEST_resetState();
+  await TEST_resetStateController();
 });
 
 describe("stateControllerListeners", () => {

src/background/stateControllerListeners.ts

@@ -15,7 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-import { tryParseSessionStorageKey } from "@/platform/state/sessionStateHelpers";
+import { tryParseSessionStorageKey } from "@/platform/state/stateHelpers";
 import type { RegistryId } from "@/types/registryTypes";
 
 /**

src/bricks/effects/pageState.test.ts

@@ -19,11 +19,11 @@ import { unsafeAssumeValidArg } from "@/runtime/runtimeTypes";
 import { brickOptionsFactory } from "@/testUtils/factories/runtimeFactories";
 import { toExpression } from "@/utils/expressionUtils";
 import { GetPageState, SetPageState } from "@/bricks/effects/pageState";
-import { TEST_resetState } from "@/contentScript/stateController";
+import { TEST_resetStateController } from "@/contentScript/stateController/stateController";
 import { MergeStrategies, StateNamespaces } from "@/platform/state/stateTypes";
 
 beforeEach(async () => {
-  await TEST_resetState();
+  await TEST_resetStateController();
 });
 
 describe("@pixiebrix/state/get", () => {

src/bricks/renderers/customForm.test.tsx

@@ -34,10 +34,10 @@ import { templates } from "@/components/formBuilder/RjsfTemplates";
 import { toExpression } from "@/utils/expressionUtils";
 import { unsafeAssumeValidArg } from "@/runtime/runtimeTypes";
 import {
-  TEST_resetState,
+  TEST_resetStateController,
   getState,
   setState,
-} from "@/contentScript/stateController";
+} from "@/contentScript/stateController/stateController";
 import type { Target } from "@/types/messengerTypes";
 import { StateNamespaces } from "@/platform/state/stateTypes";
 
@@ -225,7 +225,7 @@ describe("form data normalization", () => {
 
 describe("CustomFormRenderer", () => {
   beforeEach(async () => {
-    await TEST_resetState();
+    await TEST_resetStateController();
     jest.clearAllMocks();
   });
 

src/contentScript/contentScriptPlatform.ts

@@ -29,9 +29,8 @@ import {
 } from "@/background/messenger/api";
 import {
   getState,
-  registerModVariables,
   setState,
-} from "@/contentScript/stateController";
+} from "@/contentScript/stateController/stateController";
 import quickBarRegistry from "@/components/quickBar/quickBarRegistry";
 import { expectContext } from "@/utils/expectContext";
 import type { PlatformCapability } from "@/platform/capabilities";
@@ -62,6 +61,7 @@ import { InteractiveLoginRequiredError } from "@/errors/authErrors";
 import { deferLogin } from "@/contentScript/integrations/deferredLoginController";
 import { selectionMenuActionRegistry } from "@/contentScript/textSelectionMenu/selectionMenuController";
 import { getExtensionVersion } from "@/utils/extensionUtils";
+import { registerModVariables } from "@/contentScript/stateController/modVariablePolicyController";
 
 /**
  * @file Platform definition for mods running in a content script

src/contentScript/messenger/registration.ts

@@ -33,7 +33,10 @@ import {
 import { getProcesses, initRobot } from "@/contentScript/uipath";
 import { checkAvailable } from "@/bricks/available";
 import notify from "@/utils/notify";
-import { getState, setState } from "@/contentScript/stateController";
+import {
+  getState,
+  setState,
+} from "@/contentScript/stateController/stateController";
 import {
   cancelTemporaryPanels,
   getPanelDefinition,

src/contentScript/stateController/modVariablePolicyController.ts

@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2024 PixieBrix, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import type { RegistryId } from "@/types/registryTypes";
+import type { ModVariablesDefinition } from "@/types/modDefinitionTypes";
+import {
+  StateNamespaces,
+  SyncPolicies,
+  type SyncPolicy,
+} from "@/platform/state/stateTypes";
+import { BusinessError } from "@/errors/businessErrors";
+import { isEmpty, pickBy } from "lodash";
+import { tryParseSessionStorageKey } from "@/platform/state/stateHelpers";
+import type { Nullishable } from "@/utils/nullishUtils";
+import { emptyModVariablesDefinitionFactory } from "@/utils/modUtils";
+import type { Storage } from "webextension-polyfill";
+import { dispatchStateChangeEvent } from "@/contentScript/stateController/stateEventHelpers";
+
+const SCHEMA_POLICY_PROP = "x-sync-policy";
+
+/**
+ * Map from mod variable name to its synchronization policy.
+ * Excludes variables with SyncPolicies.NONE.
+ */
+type VariableSyncPolicyMapping = Record<
+  string,
+  Exclude<SyncPolicy, typeof SyncPolicies.NONE>
+>;
+
+/**
+ * Map from mod id to its variable synchronization policy.
+ * @since 2.1.3
+ */
+export const modSyncPolicies = new Map<RegistryId, VariableSyncPolicyMapping>();
+
+export function getSyncedVariableNames(modId: RegistryId) {
+  const modPolicy = modSyncPolicies.get(modId) ?? {};
+
+  const tabVariableNames = Object.keys(
+    pickBy(modPolicy ?? {}, (x) => x === SyncPolicies.TAB),
+  );
+  const sessionVariableNames = Object.keys(
+    pickBy(modPolicy ?? {}, (x) => x === SyncPolicies.SESSION),
+  );
+  const syncedVariableNames = [...tabVariableNames, ...sessionVariableNames];
+
+  return {
+    tab: tabVariableNames,
+    session: sessionVariableNames,
+    synced: syncedVariableNames,
+  };
+}
+
+export function mapModVariablesToModSyncPolicy(
+  variables: ModVariablesDefinition,
+): VariableSyncPolicyMapping {
+  return Object.fromEntries(
+    Object.entries(variables.schema.properties ?? {})
+      .map(([key, definition]) => {
+        // eslint-disable-next-line security/detect-object-injection -- constant
+        const variablePolicy = (definition as UnknownObject)[
+          SCHEMA_POLICY_PROP
+        ] as SyncPolicy | undefined;
+
+        if (variablePolicy && variablePolicy !== SyncPolicies.NONE) {
+          if (
+            ![SyncPolicies.SESSION, SyncPolicies.TAB].includes(variablePolicy)
+          ) {
+            throw new BusinessError(
+              `Unsupported sync policy: ${variablePolicy}`,
+            );
+          }
+
+          return [
+            key,
+            variablePolicy as Exclude<SyncPolicy, typeof SyncPolicies.NONE>,
+          ];
+        }
+
+        return null;
+      })
+      .filter((x) => x != null),
+  ) as VariableSyncPolicyMapping;
+}
+
+// Keep as separate method so it's safe to call addListener multiple times with the listener
+function onSessionStorageChange(
+  change: Record<string, Storage.StorageChange>,
+  areaName: string,
+): void {
+  if (areaName === "session") {
+    for (const key of Object.keys(change)) {
+      const slot = tryParseSessionStorageKey(key);
+
+      if (slot) {
+        dispatchStateChangeEvent({
+          namespace: StateNamespaces.MOD,
+          blueprintId: slot.modId,
+        });
+      }
+    }
+  }
+}
+
+/**
+ * Register variables and their synchronization policy for a mod.
+ * @param modId the mod registry id
+ * @param variables the mod variables definition containing their synchronization policy. If nullish, a blank policy
+ * is registered.
+ * @see emptyModVariablesDefinitionFactory
+ */
+export function registerModVariables(
+  modId: RegistryId,
+  variables: Nullishable<ModVariablesDefinition>,
+): void {
+  const modSyncPolicy = mapModVariablesToModSyncPolicy(
+    variables ?? emptyModVariablesDefinitionFactory(),
+  );
+  modSyncPolicies.set(modId, modSyncPolicy);
+
+  // If any variables are set to sync, listen for changes to session storage to notify the mods running on this page
+  if (!isEmpty(modSyncPolicy)) {
+    browser.storage.onChanged.addListener(onSessionStorageChange);
+  }
+}

src/contentScript/stateController.test.ts → src/contentScript/stateController/stateController.test.ts

@@ -17,20 +17,20 @@
 
 import {
   setState,
-  registerModVariables,
   getState,
-  TEST_resetState,
-} from "@/contentScript/stateController";
+  TEST_resetStateController,
+} from "@/contentScript/stateController/stateController";
 import { modComponentRefFactory } from "@/testUtils/factories/modComponentFactories";
 import {
   MergeStrategies,
   STATE_CHANGE_JS_EVENT_TYPE,
   StateNamespaces,
 } from "@/platform/state/stateTypes";
 import type { JSONSchema7Definition } from "json-schema";
+import { registerModVariables } from "@/contentScript/stateController/modVariablePolicyController";
 
 beforeEach(async () => {
-  await TEST_resetState();
+  await TEST_resetStateController();
 });
 
 describe("pageState", () => {