throw specific error on decrypt if key not found (#16)

* throw specific error on decrypt key not found

* let -> const

* convertToError instead of throwing it directly

* convert error checks to class member

src/Vault.ts

@@ -40,6 +40,8 @@ export class VaultRequestError extends VaultError {
     }
 }
 
+export class VaultDecryptionKeyNotFoundError extends VaultRequestError {}
+
 export interface VaultRequestOptions {
     retryWithTokenRenew?: boolean;
     acceptedReturnCodes?: number[];
@@ -172,12 +174,32 @@ export class Vault {
                     body: res.body,
                 };
             }
-            throw new VaultRequestError(
+            const tmpErr = new VaultRequestError(
                 `Request to ${requestOptions.uri.toString()} failed (Status ${errorResponse.statusCode})`,
                 errorResponse,
             );
+
+            throw this.convertToSpecificError(tmpErr);
         }
 
         return res.body;
     }
+
+    private convertToSpecificError(error: VaultRequestError): VaultRequestError {
+        if (this.checkError(error, 400, "encryption key not found")) {
+            return new VaultDecryptionKeyNotFoundError(`DecryptionKeyNotFound: ${error.message}`, error.response);
+        }
+        return error;
+    }
+
+    private checkError(error: VaultRequestError, expectedCode: number, expectedMsg: string): boolean {
+        const { statusCode, body } = error.response;
+        if (expectedCode !== statusCode) {
+            return false;
+        }
+
+        const errors = body?.errors ?? [];
+
+        return errors.some((e) => e.includes(expectedMsg));
+    }
 }

tests/engines/transit.spec.ts

@@ -1,4 +1,4 @@
-import { Vault } from "../../src";
+import { Vault, VaultDecryptionKeyNotFoundError } from "../../src";
 import { TransitVaultClient } from "../../src";
 import * as util from "util";
 
@@ -133,8 +133,7 @@ describe("Transit Vault Client", () => {
             try {
                 await client.decryptText("unknownkey", encrypted);
             } catch (err) {
-                testLogger(err.response.body.errors);
-                expect(err.response.statusCode).toEqual(400);
+                expect(err).toBeInstanceOf(VaultDecryptionKeyNotFoundError);
             }
         });
 
@@ -153,8 +152,7 @@ describe("Transit Vault Client", () => {
                     ],
                 });
             } catch (err) {
-                testLogger(err.response.body.errors);
-                expect(err.response.statusCode).toEqual(400);
+                expect(err).toBeInstanceOf(VaultDecryptionKeyNotFoundError);
             }
         });
     });