Get variables

pm.environment.get("variable_key");
pm.globals.get("variable_key");
pm.variables.get("variable_key");
pm.collectionVariables.get("variable_key");

Set variables

pm.environment.set("variable_key", "variable_value");
pm.globals.set("variable_key", "variable_value");
pm.collectionVariables.set("variable_key", "variable_value");

Unset variables

pm.environment.unset("variable_key");
pm.globals.unset("variable_key");
pm.collectionVariables.unset("variable_key");

Send a request

pm.sendRequest("https://postman-echo.com/get", function (err, response) {
    console.log(response.json());
});

Status code: Code is 200

pm.test("Status code is 200", function () {
    pm.response.to.have.status(200);
});

Response body: Contains string

pm.test("Body matches string", function () {
    pm.expect(pm.response.text()).to.include("string_you_want_to_search");
});

Response body: JSON value check

pm.test("Your test name", function () {
    var jsonData = pm.response.json();
    pm.expect(jsonData.value).to.eql(100);
});

Response body: is equal to a string

pm.test("Body is correct", function () {
    pm.response.to.have.body("response_body_string");
});

Response headers: Content-Type header check

pm.test("Content-Type is present", function () {
    pm.response.to.have.header("Content-Type");
});

Response time is less than 200ms

pm.test("Response time is less than 200ms", function () {
    pm.expect(pm.response.responseTime).to.be.below(200);
});

Status code: Successful POST request

pm.test("Successful POST request", function () {
    pm.expect(pm.response.code).to.be.oneOf([201, 202]);
});

Status code: Code name has string

pm.test("Status code name has string", function () {
    pm.response.to.have.status("Created");
});

Response body: Convert XML body to a JSON Object

var jsonObject = xml2Json(responseBody);

Use Tiny Validator for JSON data

var schema = {
    "items": {
        "type": "boolean"
    }
};
var data1 = [true, false];
var data2 = [true, 123];
pm.test('Schema is valid', function () {
    pm.expect(tv4.validate(data1, schema)).to.be.true;
    pm.expect(tv4.validate(data2, schema)).to.be.true;
});