test tags

[mfulton26]

I want a way to easily run a subset of tests based on tags (unit, integration, e2e, fast, slow, smoke, etc.).

Status quo

Command line filtering makes this possible with patterns but it is awkward:

something.test.ts

Deno.test("something tag::slow tag::integration", () => {/* ... */});

example

deno test --filter "/\btag::slow\b/" # "tag::slow" isn't sufficient as it would match "tag::slowest", etc.

Using negative lookaheads (which I'm not even sure deno test --filter supports) is even more awkward for specifying tags not to run and patterns get more complex when you want to include some tags but not other.

Encoding tags into test names also creates noise in the test report that isn't desirable, especially when tests have multiple tags.

Proposal

declare namespace Deno {
  interface TestDefinition {
    tags?: string[];
  }
}

something.test.ts

Deno.test("something", { tags: ["slow", "integration"] }, () => {/* ... */});

Command line tag expression ideas

JavaScript-like boolean operators

deno test --tags slow
deno test --tags 'fast && smoke'
deno test --tags 'e2e && !slow'
deno test --tags '(fast || smoke) && !slow'

note that ! has to be used inside single quotes (') rather than double quotes (")

predicate-like

deno test --tags "slow"
deno test --tags "fast and slow"
deno test --tags "e2e and not(slow)"
deno test --tags "(fast or smoke) and not(slow)"

note that not() is function-like, this might not be necessary but made sense at the time of writing

cucumber-like

deno test --tags "@slow"
deno test --tags "@fast and @slow"
deno test --tags "@e2e and not @slow"
deno test --tags "(@fast or @smoke) and not @slow"

see Tag expressions - Cucumber Reference - Cucumber Documentation