🎭 playwright-advanced-har

 

Playwright-advanced-har is a library that allows various use-cases for network record-and-playback, including:

- ignoring post data and get arguments
- ignoring the base-url when serving HAR files (good when you record network in test environment and play on staging/production)
- ignoring aborted requests and requests that had errors

install

``bash
npm install playwright-advanced-har
`

usage

The playwright-advanced-har provides a playwright fixture called advancedRouteFromHAR.
Here is an example of using a custom matcher to ignore 500 status code errors:

`typescript
import { test, defaultMatcher, customMatcher } from "playwright-advanced-har";

test("don't route responses that have errors", async ({ page, advancedRouteFromHAR }) => {
await advancedRouteFromHAR("tests/har/first-has-error.har", {
matcher: (request, entry) => {
if (entry.response.status >= 500 && entry.response.status < 600) {
return -1;
}
return defaultMatcher(request, entry);
},
});

await page.goto("https://noam-gaash.co.il");
await page.getByText("Hello World").waitFor();
});
`

The matcher arguments is a callback function that receives the request and the HAR entry and returns a number.
The number indicates how "good" the response is. Negative numbers (such as -1) tells the router to ignore the entry, while positive numbers indicates the entry is a qualified candidate to be routed from.

examples

ignoring port numbers:

`typescript
test("ignore port number", async ({ page, advancedRouteFromHAR }) => {
await advancedRouteFromHAR("tests/har/different-port.har", {
matcher: customMatcher({
urlComparator(a, b) {
a = a.replace(/:\d+/, "");
b = b.replace(/:\d+/, "");
return a === b;
},
}),
});
await page.goto("https://noam-gaash.co.il");
await page.getByText("from different port").waitFor();
});
`

choosing arbitrary responses:

`typescript
test("pick arbirtrary response", async ({ page, advancedRouteFromHAR }) => {
// good when you're testing a long polling requests
await advancedRouteFromHAR("tests/har/differentNumbers.har", {
matcher: customMatcher({
scoring() {
return Math.random();
},
}),
});
await page.goto("https://noam-gaash.co.il");
await page.getByText("1234").waitFor();
});
`

apply post-proccessing on the chosen HAR entry:

`typescript
test("get the largest number... squared!", async ({ page, advancedRouteFromHAR }) => {
// the file contains 3 responses - 42, 1234, 5
await advancedRouteFromHAR("tests/har/differentNumbers.har", {
matcher: {
postProcess(entry) {
entry.response.content.text = (parseInt(entry.response.content.text || "0") ** 2).toString();
return entry;
},
matchFunction: customMatcher({
scoring: (request, entry) => parseInt(entry.response.content.text || "0"),
}),
}
});
await page.goto("https://noam-gaash.co.il");
await page.getByText((1234**2).toString()).waitFor();
});
`

for more examples, please see our tests directory

Contribution

Contributions are welcome!
Please open an issue with a use-case before opening a PR, so we can discuss it. Make sure you add tests and run npm run test before commiting.

Install dependencies

`bash
npm install
`

Run tests

`bash
npm test
``