Decompose and expose preprocessing checks (#402)

* Decompose and expose preprocessing checks * Remove new enum
decentralized-identity · Jun 21, 2023 · 9499d13 · 9499d13
1 parent 098427b
commit 9499d13
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diff --git a/README.md b/README.md
@@ -3,7 +3,7 @@
 # Decentralized Web Node (DWN) SDK
 
 Code Coverage
-![Statements](https://img.shields.io/badge/statements-97.26%25-brightgreen.svg?style=flat) ![Branches](https://img.shields.io/badge/branches-94.27%25-brightgreen.svg?style=flat) ![Functions](https://img.shields.io/badge/functions-93.6%25-brightgreen.svg?style=flat) ![Lines](https://img.shields.io/badge/lines-97.26%25-brightgreen.svg?style=flat)
+![Statements](https://img.shields.io/badge/statements-97.26%25-brightgreen.svg?style=flat) ![Branches](https://img.shields.io/badge/branches-94%25-brightgreen.svg?style=flat) ![Functions](https://img.shields.io/badge/functions-93.62%25-brightgreen.svg?style=flat) ![Lines](https://img.shields.io/badge/lines-97.26%25-brightgreen.svg?style=flat)
 
 ## Introduction
 

diff --git a/src/dwn.ts b/src/dwn.ts
@@ -89,7 +89,7 @@ export class Dwn {
    * @param tenant The tenant DID to route the given message to.
    */
   public async processMessage(tenant: string, rawMessage: any, dataStream?: Readable): Promise<MessageReply> {
-    const errorMessageReply = await this.preprocessingChecks(tenant, rawMessage);
+    const errorMessageReply = await this.validateTenant(tenant) ?? await this.validateMessageIntegrity(rawMessage);
     if (errorMessageReply !== undefined) {
       return errorMessageReply;
     }
@@ -108,7 +108,9 @@ export class Dwn {
    * Handles a `RecordsQuery` message.
    */
   public async handleRecordsQuery(tenant: string, message: RecordsQueryMessage): Promise<RecordsQueryReply> {
-    const errorMessageReply = await this.preprocessingChecks(tenant, message, DwnInterfaceName.Records, DwnMethodName.Query);
+    const errorMessageReply =
+      await this.validateTenant(tenant) ??
+      await this.validateMessageIntegrity(message, DwnInterfaceName.Records, DwnMethodName.Query);
     if (errorMessageReply !== undefined) {
       return errorMessageReply;
     }
@@ -121,7 +123,9 @@ export class Dwn {
    * Handles a `RecordsRead` message.
    */
   public async handleRecordsRead(tenant: string, message: RecordsReadMessage): Promise<RecordsReadReply> {
-    const errorMessageReply = await this.preprocessingChecks(tenant, message, DwnInterfaceName.Records, DwnMethodName.Read);
+    const errorMessageReply =
+      await this.validateTenant(tenant) ??
+      await this.validateMessageIntegrity(message, DwnInterfaceName.Records, DwnMethodName.Read);
     if (errorMessageReply !== undefined) {
       return errorMessageReply;
     }
@@ -134,7 +138,9 @@ export class Dwn {
    * Handles a `MessagesGet` message.
    */
   public async handleMessagesGet(tenant: string, message: MessagesGetMessage): Promise<MessagesGetReply> {
-    const errorMessageReply = await this.preprocessingChecks(tenant, message, DwnInterfaceName.Messages, DwnMethodName.Get);
+    const errorMessageReply =
+      await this.validateTenant(tenant) ??
+      await this.validateMessageIntegrity(message, DwnInterfaceName.Messages, DwnMethodName.Get);
     if (errorMessageReply !== undefined) {
       return errorMessageReply;
     }
@@ -147,7 +153,9 @@ export class Dwn {
    * Privileged method for writing a pruned initial `RecordsWrite` to a DWN without needing to supply associated data.
    */
   public async synchronizePrunedInitialRecordsWrite(tenant: string, message: RecordsWriteMessage): Promise<MessageReply> {
-    const errorMessageReply = await this.preprocessingChecks(tenant, message, DwnInterfaceName.Records, DwnMethodName.Write);
+    const errorMessageReply =
+      await this.validateTenant(tenant) ??
+      await this.validateMessageIntegrity(message, DwnInterfaceName.Records, DwnMethodName.Write);
     if (errorMessageReply !== undefined) {
       return errorMessageReply;
     }
@@ -162,21 +170,32 @@ export class Dwn {
   }
 
   /**
-   * Common checks for handlers.
+   * Checks tenant gate to see if tenant is allowed.
+   * @param tenant The tenant DID to route the given message to.
+   * @returns BaseMessageReply if the message has an integrity error, otherwise undefined.
    */
-  private async preprocessingChecks(
-    tenant: string,
-    rawMessage: any,
-    expectedInterface?: DwnInterfaceName,
-    expectedMethod?: DwnMethodName
-  ): Promise<BaseMessageReply | undefined> {
+  public async validateTenant(tenant: string): Promise<MessageReply | undefined> {
     const isTenant = await this.tenantGate.isTenant(tenant);
     if (!isTenant) {
       return new MessageReply({
         status: { code: 401, detail: `${tenant} is not a tenant` }
       });
     }
+  }
+
+  /**
+   * Validates structure of DWN message
+   * @param tenant The tenant DID to route the given message to.
+   * @param dwnMessageInterface The interface of DWN message.
+   * @param dwnMessageMethod The interface of DWN message.
 
+   * @returns BaseMessageReply if the message has an integrity error, otherwise undefined.
+   */
+  public async validateMessageIntegrity(
+    rawMessage: any,
+    expectedInterface?: DwnInterfaceName,
+    expectedMethod?: DwnMethodName,
+  ): Promise<BaseMessageReply | undefined> {
     // Verify interface and method
     const dwnInterface = rawMessage?.descriptor?.interface;
     const dwnMethod = rawMessage?.descriptor?.method;
@@ -185,6 +204,7 @@ export class Dwn {
         status: { code: 400, detail: `Both interface and method must be present, interface: ${dwnInterface}, method: ${dwnMethod}` }
       });
     }
+
     if (expectedInterface !== undefined && expectedInterface !== dwnInterface) {
       return new MessageReply({
         status: { code: 400, detail: `Expected interface ${expectedInterface}, received ${dwnInterface}` }
@@ -203,8 +223,6 @@ export class Dwn {
     } catch (error) {
       return MessageReply.fromError(error, 400);
     }
-
-    return undefined;
   }
 };