diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 64b9d344be..ec764033b0 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -263,7 +263,6 @@ jobs:
                     "tests/end_to_end/candid_rpc/class_syntax/timers",
                     "tests/end_to_end/candid_rpc/class_syntax/tuple_types",
                     "tests/end_to_end/candid_rpc/class_syntax/update",
-                    "tests/end_to_end/candid_rpc/class_syntax/vanilla_js",
                   ]
                   END
                   )
diff --git a/src/lib/stable/globals.ts b/src/lib/stable/globals.ts
new file mode 100644
index 0000000000..6f6e583e2b
--- /dev/null
+++ b/src/lib/stable/globals.ts
@@ -0,0 +1,4 @@
+import { TextDecoder, TextEncoder } from 'text-encoding';
+
+globalThis.TextDecoder = TextDecoder;
+globalThis.TextEncoder = TextEncoder;
diff --git a/src/lib/stable/index.ts b/src/lib/stable/index.ts
index 79a172ba8c..5e9a4e3b8b 100644
--- a/src/lib/stable/index.ts
+++ b/src/lib/stable/index.ts
@@ -1,3 +1,4 @@
+import './globals';
 export * from '../stable_structures/stable_b_tree_map';
 export * from '../stable_structures/stable_json';
 export { heartbeat } from './heartbeat';
diff --git a/src/lib/stable/system_types/rejection_code.ts b/src/lib/stable/system_types/rejection_code.ts
index 9b6fd09520..5d7d29a98c 100644
--- a/src/lib/stable/system_types/rejection_code.ts
+++ b/src/lib/stable/system_types/rejection_code.ts
@@ -1,20 +1,16 @@
-import { IDL } from '..';
+import { IDL } from '@dfinity/candid';
 
 /**
  * Indicates an error was encountered during a canister method.
  */
 export const RejectionCode = IDL.Variant({
-    NoError: IDL.Null
-    // TODO we are getting some sort of error when all of these are added in. It
-    // is happening during what looks like a sort of the properties (which might
-    // explain why one is fine (it doesn't need to be sorted)). The error is
-    // ReferenceError: 'TextEncoder' is not defined
-    // SysFatal: IDL.Null,
-    // SysTransient: IDL.Null,
-    // DestinationInvalid: IDL.Null
-    // CanisterReject: IDL.Null,
-    // CanisterError: IDL.Null,
-    // Unknown: IDL.Null,
+    NoError: IDL.Null,
+    SysFatal: IDL.Null,
+    SysTransient: IDL.Null,
+    DestinationInvalid: IDL.Null,
+    CanisterReject: IDL.Null,
+    CanisterError: IDL.Null,
+    Unknown: IDL.Null
 });
 
 export type RejectionCode =
diff --git a/tests/end_to_end/candid_rpc/class_syntax/ledger_canister/src/ledger_canister/index.ts b/tests/end_to_end/candid_rpc/class_syntax/ledger_canister/src/ledger_canister/index.ts
index 84128b1e10..7bd62cc221 100644
--- a/tests/end_to_end/candid_rpc/class_syntax/ledger_canister/src/ledger_canister/index.ts
+++ b/tests/end_to_end/candid_rpc/class_syntax/ledger_canister/src/ledger_canister/index.ts
@@ -25,6 +25,10 @@ export default class {
         fee: bigint,
         createdAtTime: [bigint] | []
     ) {
+        const created_at_time =
+            createdAtTime.length === 0
+                ? []
+                : [{ timestamp_nanos: createdAtTime[0] }];
         return await call(getIcpCanisterPrincipal(), 'transfer', {
             paramIdls: [TransferArgs],
             returnIdl: TransferResult,
@@ -39,7 +43,7 @@ export default class {
                     },
                     from_subaccount: [],
                     to: binaryAddressFromAddress(to),
-                    created_at_time: createdAtTime
+                    created_at_time
                 }
             ]
         });
diff --git a/tests/end_to_end/candid_rpc/class_syntax/management_canister/src/index.ts b/tests/end_to_end/candid_rpc/class_syntax/management_canister/src/index.ts
index c8c80b1259..6ad93cc077 100644
--- a/tests/end_to_end/candid_rpc/class_syntax/management_canister/src/index.ts
+++ b/tests/end_to_end/candid_rpc/class_syntax/management_canister/src/index.ts
@@ -214,10 +214,10 @@ export default class {
     @update([CanisterStatusArgs], CanisterStatusResult)
     async getCanisterStatus(
         args: CanisterStatusArgs
-    ): Promise<CanisterInfoResult> {
+    ): Promise<CanisterStatusResult> {
         return await call('aaaaa-aa', 'canister_status', {
             paramIdls: [CanisterStatusArgs],
-            returnIdl: CanisterInfoResult,
+            returnIdl: CanisterStatusResult,
             args: [args]
         });
     }
diff --git a/tests/end_to_end/candid_rpc/class_syntax/rejections/src/rejections/index.ts b/tests/end_to_end/candid_rpc/class_syntax/rejections/src/rejections/index.ts
index 29ddee0727..ccc42070b6 100644
--- a/tests/end_to_end/candid_rpc/class_syntax/rejections/src/rejections/index.ts
+++ b/tests/end_to_end/candid_rpc/class_syntax/rejections/src/rejections/index.ts
@@ -10,7 +10,9 @@ import {
 export default class {
     @update([], RejectionCode)
     async getRejectionCodeNoError() {
-        await call(getSomeCanisterPrincipal(), 'accept');
+        await call(getSomeCanisterPrincipal(), 'accept', {
+            returnIdl: IDL.Bool
+        });
 
         return rejectCode();
     }
@@ -30,6 +32,7 @@ export default class {
     async getRejectionCodeCanisterReject() {
         try {
             await call(getSomeCanisterPrincipal(), 'reject', {
+                paramIdls: [IDL.Text],
                 args: ['reject']
             });
         } catch (error) {
@@ -54,6 +57,7 @@ export default class {
     async getRejectionMessage(message: string) {
         try {
             await call(getSomeCanisterPrincipal(), 'reject', {
+                paramIdls: [IDL.Text],
                 args: [message]
             });
         } catch (error) {
diff --git a/tests/end_to_end/candid_rpc/class_syntax/rejections/src/some_canister/index.ts b/tests/end_to_end/candid_rpc/class_syntax/rejections/src/some_canister/index.ts
index e7d3c20094..ed7127e91c 100644
--- a/tests/end_to_end/candid_rpc/class_syntax/rejections/src/some_canister/index.ts
+++ b/tests/end_to_end/candid_rpc/class_syntax/rejections/src/some_canister/index.ts
@@ -2,17 +2,17 @@ import { IDL, query, reject } from 'azle';
 
 export default class {
     @query([IDL.Text], IDL.Empty, { manual: true })
-    reject(message: string) {
+    reject(message: string): void {
         reject(message);
     }
 
     @query([], IDL.Bool)
-    accept() {
+    accept(): boolean {
         return true;
     }
 
     @query([], IDL.Empty, { manual: true })
-    error() {
+    error(): void {
         // This errors because neither ic.reject nor ic.reply were called
     }
 }
diff --git a/tests/end_to_end/candid_rpc/class_syntax/vanilla_js/package-lock.json b/tests/end_to_end/candid_rpc/class_syntax/vanilla_js/package-lock.json
index 1edbfb0b77..ade8d9bd75 100644
--- a/tests/end_to_end/candid_rpc/class_syntax/vanilla_js/package-lock.json
+++ b/tests/end_to_end/candid_rpc/class_syntax/vanilla_js/package-lock.json
@@ -1,10 +1,9 @@
 {
-    "name": "vanilla_js_end_to_end_test_functional_syntax",
+    "name": "vanilla_js",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
-            "name": "vanilla_js_end_to_end_test_functional_syntax",
             "dependencies": {
                 "azle": "0.22.0",
                 "js-sha256": "0.9.0"
@@ -17,6 +16,7 @@
             }
         },
         "../../../../../examples/vanilla_js": {
+            "name": "vanilla_js_end_to_end_test_functional_syntax",
             "dev": true,
             "dependencies": {
                 "azle": "0.22.0",
@@ -24,6 +24,8 @@
             },
             "devDependencies": {
                 "@dfinity/agent": "^0.19.2",
+                "jest": "^29.7.0",
+                "ts-jest": "^29.1.5",
                 "ts-node": "^10.9.1",
                 "typescript": "^5.2.2"
             }