html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/datasette/issues/1165#issuecomment-752780000,https://api.github.com/repos/simonw/datasette/issues/1165,752780000,MDEyOklzc3VlQ29tbWVudDc1Mjc4MDAwMA==,9599,2020-12-30T22:41:25Z,2020-12-30T22:41:25Z,OWNER,Jest works with Puppeteer: https://jestjs.io/docs/en/puppeteer,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",776635426,
https://github.com/simonw/datasette/issues/1165#issuecomment-752779820,https://api.github.com/repos/simonw/datasette/issues/1165,752779820,MDEyOklzc3VlQ29tbWVudDc1Mjc3OTgyMA==,9599,2020-12-30T22:40:28Z,2020-12-30T22:40:28Z,OWNER,"I don't know if Jest on the command-line is the right tool for this. It works for the `plugins.js` script but I'm increasingly going to want to start adding tests for browser JavaScript features - like the https://github.com/simonw/datasette/blob/0.53/datasette/static/table.js script - which will need to run in a browser.

So maybe I should just find a browser testing solution and figure out how to run that under CI in GitHub Actions. Maybe https://www.cypress.io/ ?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",776635426,
https://github.com/simonw/datasette/issues/1165#issuecomment-752779490,https://api.github.com/repos/simonw/datasette/issues/1165,752779490,MDEyOklzc3VlQ29tbWVudDc1Mjc3OTQ5MA==,9599,2020-12-30T22:38:43Z,2020-12-30T22:38:43Z,OWNER,Turned that into a TIL: https://til.simonwillison.net/javascript/jest-without-package-json,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",776635426,
https://github.com/simonw/datasette/issues/1165#issuecomment-752777744,https://api.github.com/repos/simonw/datasette/issues/1165,752777744,MDEyOklzc3VlQ29tbWVudDc1Mjc3Nzc0NA==,9599,2020-12-30T22:30:24Z,2020-12-30T22:30:24Z,OWNER,"https://www.valentinog.com/blog/jest/ was useful.

I created a `static/__tests__` folder and added this file as `plugins.spec.js`:

```javascript
const datasette = require(""../plugins.js"");

describe(""Datasette Plugins"", () => {
  test(""it should have datasette.plugins"", () => {
    expect(!!datasette.plugins).toEqual(true);
  });
  test(""registering a plugin should work"", () => {
    datasette.plugins.register(""numbers"", (a, b) => a + b, [""a"", ""b""]);
    var result = datasette.plugins.call(""numbers"", { a: 1, b: 2 });
    expect(result).toEqual([3]);
    datasette.plugins.register(""numbers"", (a, b) => a * b, [""a"", ""b""]);
    var result2 = datasette.plugins.call(""numbers"", { a: 1, b: 2 });
    expect(result2).toEqual([3, 2]);
  });
});
```

In `static/plugins.js` I put this:
```javascript
var datasette = datasette || {};
datasette.plugins = (() => {
    var registry = {};
    return {
        register: (hook, fn, parameters) => {
            if (!registry[hook]) {
                registry[hook] = [];
            }
            registry[hook].push([fn, parameters]);
        },
        call: (hook, args) => {
            args = args || {};
            var results = [];
            (registry[hook] || []).forEach(([fn, parameters]) => {
                /* Call with the correct arguments */
                var result = fn.apply(fn, parameters.map(parameter => args[parameter]));
                if (result !== undefined) {
                    results.push(result);
                }
            });
            return results;
        }
    };
})();

module.exports = datasette;
```
Note the `module.exports` line at the end.

Then inside `static/` I ran the following command:

```
% npx jest -c '{}'
 PASS  __tests__/plugins.spec.js
  Datasette Plugins
    ✓ it should have datasette.plugins (3 ms)
    ✓ registering a plugin should work (1 ms)

Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        1.163 s
Ran all test suites.
```
The `-c {}` was necessary because I didn't have a Jest configuration or a `package.json`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",776635426,
https://github.com/simonw/datasette/issues/1165#issuecomment-752757910,https://api.github.com/repos/simonw/datasette/issues/1165,752757910,MDEyOklzc3VlQ29tbWVudDc1Mjc1NzkxMA==,9599,2020-12-30T21:04:18Z,2020-12-30T21:04:18Z,OWNER,https://jestjs.io/ looks worth trying here.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",776635426,