code coverage

[connorjclark]

seems coverage was removed? I had a hunch about some code that could be removed, and wanted to confirm if it was hit in any tests.

[fabiosantoscode]

Code coverage was removed for several reasons. My reason was that we would need a coverage tool for our custom test/run-tests.js machinery. If any of those tests (which make most of our tests) cover the code you want to remove, you wouldn't know even if we had coverage :(

I think adding coverage functionality to our custom testing machinery is out of scope for this project, so I have to close the issue :)

[connorjclark]

Fair enough, coverage would be useful but I understand it'd be a bit of work to add to the project's test harness. For the benefit of anyone out there reading this issue and interested in doing the work, I'll ask you - would you accept a PR that added coverage?

Related to tests, I found mocha tests to be cumbersome when run via run-tests.js for a couple reasons: 1) no way to filter what tests run and 2) when an assertion fails it does not describe what differed. I only get a diff when using mocha directly. It took me awhile to figure out I should just use the mocha binary. Perhaps I should add some documentation about .node_modules/.bin/mocha test/mocha --grep ... to clear things up?

(example of above)

diff --git a/test/mocha/cli.js b/test/mocha/cli.js
index bc6c82af..d2c11475 100644
--- a/test/mocha/cli.js
+++ b/test/mocha/cli.js
@@ -35,7 +35,7 @@ describe("bin/uglifyjs", function() {
         exec(command, function (err, stdout) {
             if (err) throw err;
 
-            assert.strictEqual(stdout, "/*@preserve*/\n\n");
+            assert.strictEqual(stdout, "/*@presezrve*/\n\n");
             done();
         });
     });

yarn test

Stack trace is gibberish and failing assertion is not printed.

node node_modules/.bin/mocha test/mocha  --grep "Should be able to filter comments correctly with just "

[nylen]

My reason was that we would need a coverage tool for our custom test/run-tests.js machinery.

Is there any documentation about this setup? Why it exists / why it's necessary?

would you accept a PR that added coverage?

I'd also like to know the answer to this.

Code coverage is especially useful for projects that are (a) complicated, and (b) expected to serve as a base for many other things. JavaScript minifiers meet both of these criteria in my opinion.