diff --git a/packages/insomnia-smoke-test/fixtures/pre-request-collection.yaml b/packages/insomnia-smoke-test/fixtures/pre-request-collection.yaml
index d6beb5944..c5bbb3561 100644
--- a/packages/insomnia-smoke-test/fixtures/pre-request-collection.yaml
+++ b/packages/insomnia-smoke-test/fixtures/pre-request-collection.yaml
@@ -750,3 +750,49 @@ resources:
           "events": {{ _.events }}
         }
     _type: request
+  - _id: req_89dade2ee9ee42fbb22d588783a9df1
+    parentId: fld_01de564274824ecaad272330339ea6b2
+    modified: 1636707449231
+    created: 1636141014552
+    url: http://127.0.0.1:4010/echo
+    name: insomnia.test
+    description: ""
+    method: POST
+    parameters: []
+    headers:
+      - name: 'Content-Type'
+        value: 'application/json'
+    authentication: {}
+    metaSortKey: -1636141014553
+    isPrivate: false
+    settingStoreCookies: true
+    settingSendCookies: true
+    settingDisableRenderRequestBody: false
+    settingEncodeUrl: true
+    settingRebuildPath: true
+    settingFollowRedirects: global
+    preRequestScript: |-
+      insomnia.test('happy tests', () => {
+        pm.expect(200).to.eql(200);
+        pm.expect('uname').to.be.a('string');
+        pm.expect('a').to.have.lengthOf(1);
+        pm.expect('xxx_customer_id_yyy').to.include("customer_id");
+        pm.expect(201).to.be.oneOf([201,202]);
+        pm.expect(199).to.be.below(200);
+        // test objects
+        pm.expect({a: 1, b: 2}).to.have.all.keys('a', 'b');
+        pm.expect({a: 1, b: 2}).to.have.any.keys('a', 'b');
+        pm.expect({a: 1, b: 2}).to.not.have.any.keys('c', 'd');
+        pm.expect({a: 1}).to.have.property('a');
+        pm.expect({a: 1, b: 2}).to.be.a('object')
+          .that.has.all.keys('a', 'b');
+      });
+      insomnia.test('unhappy tests', () => {
+        pm.expect(199).to.eql(200);
+        pm.expect(199).to.be.oneOf([201,202]);
+      });
+    body:
+      mimeType: "application/json"
+      text: |-
+        {}
+    _type: request
diff --git a/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts b/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts
index 247930fc2..2a028882b 100644
--- a/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts
+++ b/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts
@@ -344,6 +344,21 @@ test.describe('pre-request features tests', async () => {
         await page.getByRole('tab', { name: 'Timeline' }).click();
         await expect(responsePane).toContainText('fixtures/certificates/fake.pfx'); // original proxy
     });
+
+    test('insomnia.test and insomnia.expect can work together ', async ({ page }) => {
+        const responsePane = page.getByTestId('response-pane');
+
+        await page.getByLabel('Request Collection').getByTestId('insomnia.test').press('Enter');
+
+        // send
+        await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+
+        // verify
+        await page.getByRole('tab', { name: 'Timeline' }).click();
+
+        await expect(responsePane).toContainText('✓ happy tests'); // original proxy
+        await expect(responsePane).toContainText('✕ unhappy tests: AssertionError: expected 199 to deeply equal 200'); // updated proxy
+    });
 });
 
 test.describe('unhappy paths', async () => {
diff --git a/packages/insomnia/src/hidden-window.ts b/packages/insomnia/src/hidden-window.ts
index c3db98cbe..a6f9f0cb1 100644
--- a/packages/insomnia/src/hidden-window.ts
+++ b/packages/insomnia/src/hidden-window.ts
@@ -36,9 +36,8 @@ const runPreRequestScript = async (
 ): Promise<RequestContext> => {
   console.log(script);
 
-  const executionContext = initInsomniaObject(context);
-  const log: string[] = [];
   // TODO: we should at least support info, debug, warn, error
+  const log: string[] = [];
   const consoleInterceptor = {
     log: (...args: any[]) => log.push(
       JSON.stringify({
@@ -49,6 +48,8 @@ const runPreRequestScript = async (
     ),
   };
 
+  const executionContext = initInsomniaObject(context, consoleInterceptor.log);
+
   const evalInterceptor = (script: string) => {
     invariant(script && typeof script === 'string', 'eval is called with invalid or empty value');
     const result = eval(script);
diff --git a/packages/insomnia/src/sdk/objects/environments.ts b/packages/insomnia/src/sdk/objects/environments.ts
index 9ed42f4cc..a98afab39 100644
--- a/packages/insomnia/src/sdk/objects/environments.ts
+++ b/packages/insomnia/src/sdk/objects/environments.ts
@@ -1,3 +1,4 @@
+import { getIntepolator } from './interpolator';
 export class Environment {
     private kvs = new Map<string, boolean | number | string>();
 
@@ -25,10 +26,9 @@ export class Environment {
         this.kvs.clear();
     };
 
-    // TODO: enable this after intepolator is introduced
-    // replaceIn = (template: string) => {
-    //     return getIntepolator().render(template, this.toObject());
-    // };
+    replaceIn = (template: string) => {
+        return getIntepolator().render(template, this.toObject());
+    };
 
     toObject = () => {
         return Object.fromEntries(this.kvs.entries());
@@ -90,10 +90,10 @@ export class Variables {
         this.local.set(variableName, variableValue);
     };
 
-    // replaceIn = (template: string) => {
-    //     const context = this.toObject();
-    //     return getIntepolator().render(template, context);
-    // };
+    replaceIn = (template: string) => {
+        const context = this.toObject();
+        return getIntepolator().render(template, context);
+    };
 
     toObject = () => {
         return [
diff --git a/packages/insomnia/src/sdk/objects/insomnia.ts b/packages/insomnia/src/sdk/objects/insomnia.ts
index d5e969e5c..025804f1e 100644
--- a/packages/insomnia/src/sdk/objects/insomnia.ts
+++ b/packages/insomnia/src/sdk/objects/insomnia.ts
@@ -1,3 +1,5 @@
+import { expect } from 'chai';
+
 import { ClientCertificate } from '../../models/client-certificate';
 import { RequestBodyParameter, RequestHeader } from '../../models/request';
 import { Settings } from '../../models/settings';
@@ -8,6 +10,7 @@ import { unsupportedError } from './properties';
 import { Request as ScriptRequest, RequestBodyOptions, RequestOptions } from './request';
 import { Response as ScriptResponse } from './response';
 import { sendRequest } from './send-request';
+import { test } from './test';
 
 export class InsomniaObject {
     public environment: Environment;
@@ -16,12 +19,16 @@ export class InsomniaObject {
     public variables: Variables;
     public request: ScriptRequest;
     private clientCertificates: ClientCertificate[];
+    private _expect = expect;
+    private _test = test;
 
     // TODO: follows will be enabled after Insomnia supports them
     private _globals: Environment;
     private _iterationData: Environment;
     private _settings: Settings;
 
+    private _log: (...msgs: any[]) => void;
+
     constructor(
         rawObj: {
             globals: Environment;
@@ -33,6 +40,7 @@ export class InsomniaObject {
             settings: Settings;
             clientCertificates: ClientCertificate[];
         },
+        log: (...msgs: any[]) => void,
     ) {
         this._globals = rawObj.globals;
         this.environment = rawObj.environment;
@@ -44,6 +52,8 @@ export class InsomniaObject {
         this.request = rawObj.request;
         this._settings = rawObj.settings;
         this.clientCertificates = rawObj.clientCertificates;
+
+        this._log = log;
     }
 
     sendRequest(
@@ -53,6 +63,14 @@ export class InsomniaObject {
         return sendRequest(request, cb, this._settings);
     }
 
+    test(msg: string, fn: () => void) {
+        this._test(msg, fn, this._log);
+    }
+
+    expect(exp: boolean | number | string | object) {
+        return this._expect(exp);
+    }
+
     // TODO: remove this after enabled globals
     get globals() {
         throw unsupportedError('globals', 'base environment');
@@ -84,6 +102,7 @@ export class InsomniaObject {
 
 export function initInsomniaObject(
     rawObj: RequestContext,
+    log: (...args: any[]) => void,
 ) {
     const globals = new Environment(rawObj.globals);
     const environment = new Environment(rawObj.environment);
@@ -188,5 +207,6 @@ export function initInsomniaObject(
             settings: rawObj.settings,
             clientCertificates: rawObj.clientCertificates,
         },
+        log,
     );
 };
diff --git a/packages/insomnia/src/sdk/objects/interpolator.ts b/packages/insomnia/src/sdk/objects/interpolator.ts
new file mode 100644
index 000000000..7d665aaaf
--- /dev/null
+++ b/packages/insomnia/src/sdk/objects/interpolator.ts
@@ -0,0 +1,34 @@
+import { configure, type ConfigureOptions, type Environment as NunjuncksEnv } from 'nunjucks';
+
+class Intepolator {
+    private engine: NunjuncksEnv;
+
+    constructor(config: ConfigureOptions) {
+        this.engine = configure(config);
+    }
+
+    render = (template: string, context: object) => {
+        // TODO: handle timeout
+        // TODO: support plugin?
+        return this.engine.renderString(template, context);
+    };
+}
+
+const intepolator = new Intepolator({
+    autoescape: false,
+    // Don't escape HTML
+    throwOnUndefined: true,
+    // Strict mode
+    tags: {
+        blockStart: '{%',
+        blockEnd: '%}',
+        variableStart: '{{',
+        variableEnd: '}}',
+        commentStart: '{#',
+        commentEnd: '#}',
+    },
+});
+
+export function getIntepolator() {
+    return intepolator;
+}
diff --git a/packages/insomnia/src/sdk/objects/request.ts b/packages/insomnia/src/sdk/objects/request.ts
index 7ec0974c7..7d68b1f01 100644
--- a/packages/insomnia/src/sdk/objects/request.ts
+++ b/packages/insomnia/src/sdk/objects/request.ts
@@ -579,6 +579,7 @@ export function mergeRequests(
             {},
         ),
         authentication: fromPreRequestAuth(updatedReq.auth),
+        preRequestScript: '',
     };
 
     return {
diff --git a/packages/insomnia/src/sdk/objects/test.ts b/packages/insomnia/src/sdk/objects/test.ts
new file mode 100644
index 000000000..14b1e56eb
--- /dev/null
+++ b/packages/insomnia/src/sdk/objects/test.ts
@@ -0,0 +1,12 @@
+export function test(
+    msg: string,
+    fn: () => void,
+    log: (message?: any, ...optionalParams: any[]) => void,
+) {
+    try {
+        fn();
+        log(`✓ ${msg}`);
+    } catch (e) {
+        log(`✕ ${msg}: ${e}`);
+    }
+}
diff --git a/packages/insomnia/src/ui/components/editors/pre-request-script-editor.tsx b/packages/insomnia/src/ui/components/editors/pre-request-script-editor.tsx
index 6f179a3b6..1ab3cf563 100644
--- a/packages/insomnia/src/ui/components/editors/pre-request-script-editor.tsx
+++ b/packages/insomnia/src/ui/components/editors/pre-request-script-editor.tsx
@@ -172,7 +172,10 @@ export const PreRequestScriptEditor: FC<Props> = ({
       }),
       settings,
       clientCertificates: [],
-    }),
+    },
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      (_msg: string, _fn: () => void) => { }
+    ),
     'insomnia',
   );