fix: migrate to github.com/mxschmitt/playwright-go v0.6100.0

[Bluebugs]

Root cause

Dependabot's weekly run and every PR's CI were failing for the same underlying reason: we were pinned to a playwright-go release published under a module path that no longer exists.

1. Dependabot aborts every gomod run (failing run)

The playwright-community GitHub org is archived; playwright-go moved back to github.com/mxschmitt/playwright-go (upstream #619). v0.6100.0 is the first release under the new path, and its go.mod declares that path. Resolving it through the old path fails:

module declares its path as: github.com/mxschmitt/playwright-go
        but was required as: github.com/playwright-community/playwright-go

Dependabot surfaces this as go_module_path_mismatch and exits non-zero for the whole run, not just for playwright-go — which is why the run was red every week even though the goproxy and testcontainers PRs were created fine. Upstream tracks the same symptom in #624.

Note that GitHub's repo redirect does still work, and every release up to v0.6000.0 still resolves through the old path. A redirect can't help here: Go verifies the module line inside the downloaded go.mod, which is exactly what stops a redirect from silently substituting a different module.

2. Every PR's CI fails

Staying on v0.5700.1 had an independent consequence. That release downloads the driver from the *.azureedge.net mirrors, retired along with the Azure CDN from Edgio, which now 404 for every driver version:

could not download driver: error: got non 200 status code: 404 (404 Not Found)
  from https://playwright.azureedge.net/builds/driver/playwright-1.57.0-linux.zip

The Playwright version step obtained the version by running the upstream CLI, which downloads that driver first. Because the failing command sat inside echo "version="$(...), its exit status was discarded and the step wrote an empty version, surfacing two steps later as an unrelated-looking error:

ERROR: failed to build: mcr.microsoft.com/playwright:v: not found

v0.6100.0 assembles the driver from npm + nodejs.org instead of the dead CDN (upstream #615), so the migration fixes this too.

Two follow-on breakages the upgrade exposed

Moving to Playwright 1.61.1 surfaced two more problems, both fixed here.

Browser servers became unreachable. Playwright 1.61 hardened WSServer.listen with hostname ??= "localhost"; 1.57 passed the hostname through to net.Server.listen, which binds all interfaces. Inside the container that means launchServer listens only on loopback and Docker's published port has nothing to forward to. It showed up twice removed from the cause — first could not get chromium port: timeout ... could not connect to http://localhost:32772, then listen EADDRINUSE: address already in use ::1:1027 once a second exec tried to start the same browser while the first unreachable server still held the port. Fixed by passing host: '0.0.0.0' explicitly, so the bind no longer depends on an upstream default.

The image tag no longer resolved. The tag was reverse-engineered from the Playwright CLI version, assuming playwright-go tags v0.{minor}{patch}.{n} for CLI 1.{minor}.{patch}. That held for 13 consecutive releases and then broke: v0.6100.0 ships CLI 1.61.1, which the convention would have written as v0.6101.0. We publish images for the v0.6100 line, so the derived tag names an image that does not exist.

Replaced with versions the Go toolchain already recorded — a consumer's own pinned playwright-ci-go version is the image tag, and failing that, playwright-go's module version gives the release line exactly. No convention to reverse-engineer.

That path only worked once a latent bug was fixed: getPlaywrightCIGoFromBuildInfo read if info, ok := debug.ReadBuildInfo(); !ok, running the lookup only when build info was absent — so it always reported failure, and would have dereferenced a nil *BuildInfo had it ever entered. Test_BuildInfoPath asserted the broken result, which is why it went unnoticed; go list was silently carrying the whole feature. With it fixed, go list is a fallback for in-repo development rather than the only working strategy.

Since neither strategy guesses, an unresolvable tag is now an error naming WithRepository rather than a docker pull for a tag that never existed.

Changes

• Migrate the module path and all imports to github.com/mxschmitt/playwright-go, bumped to v0.6100.0 (Playwright CLI 1.57.0 → 1.61.1). The archived path is still recognised when resolving versions, so consumers mid-migration keep working.
• Read the pinned CLI version from playwright-go via a small internal/cmd/playwrightversion helper instead of running the upstream CLI, so a metadata lookup no longer needs a CDN. Plus set -euo pipefail and an empty-value guard in the version step of ci.yml and main.yml.
• host: '0.0.0.0' on launchServer in chromium.js / firefox.js / webkit.js.
• Resolve the image tag from module versions; fix the inverted build-info guard; drop the CLI-version formula and the v0.5101.0 workaround that went with it.
• Refresh testdata/screenshot-webkit.png for WebKit's rendering changes, following the same procedure the Dependabot workflow uses (both failed captures were byte-identical before promoting).

No Dependabot ignore rule is needed: once the old path is gone from go.mod, there is nothing left that fails to resolve.

Verification

Run locally against a Docker image built from this branch (PLAYWRIGHT_VERSION=1.61.1):

• Full test suite green, including the Docker-backed browser tests — 24 unit tests plus Test_HelloWorld and Test_OverlapLifecycle on chromium and webkit.
• examples green with no PLAYWRIGHTCI_* overrides, which exercises tag resolution end to end: it resolved v0.6100.0 on its own and pulled the matching image.
• Driver install verified against v0.6100.0 on a machine where every azureedge mirror 404s — succeeds in ~7s.
• go build ./..., go vet ./..., gofmt -l ., golangci-lint run — all clean.
• The bind and tag-convention findings were confirmed against the extracted playwright-core 1.57.0 and 1.61.1 packages and all 14 playwright-go releases, not inferred from the symptom.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR migrates the project from the archived github.com/playwright-community/playwright-go module path to github.com/mxschmitt/playwright-go at v0.6100.0, addressing Dependabot module path mismatch failures and the retired Azure CDN driver download failures. It also updates CI to determine the Playwright CLI version without invoking the upstream Playwright CLI command.

Changes:

• Bump and migrate Playwright Go dependency/imports to github.com/mxschmitt/playwright-go v0.6100.0.
• Add a small helper (internal/cmd/playwrightversion) and update workflows to read the pinned Playwright CLI version via Go code.
• Harden CI version-detection steps with set -euo pipefail and explicit empty-value guards.

Reviewed changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
README.md	Updates Playwright-Go link to the new upstream module org/path.
go.mod	Switches required module to github.com/mxschmitt/playwright-go v0.6100.0.
go.sum	Removes old module checksums and adds new ones for mxschmitt/playwright-go.
install.go	Migrates import path used by installation logic.
browsers.go	Migrates import path for browser API surface.
container.go	Updates module detection to prefer mxschmitt path while retaining fallback for legacy consumers.
playwrightci_test.go	Updates tests to import the new module path.
benchmark_test.go	Updates benchmarks to import the new module path.
examples/example_test.go	Updates examples to import the new module path.
internal/cmd/playwrightversion/main.go	New helper to print the pinned Playwright CLI version without running upstream CLI.
.github/workflows/ci.yml	Uses helper + strict shell settings to reliably compute Playwright versions.
.github/workflows/main.yml	Same Playwright version computation for release/tag pipeline.
.github/workflows/pr.yml	Updates Dependabot/Playwright-Go conditional checks to match the new module path.
CLAUDE.md	Updates documentation reference to the new Playwright-Go module path.

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[Copilot]

Pull request overview

Copilot reviewed 19 out of 21 changed files in this pull request and generated no new comments.

[github-actions]

Golang test coverage difference report

Coverage increased by 3.04%. 🏅 Keep it up 🏅

Package report

package                                                                            before    after    delta
-------                                                                           -------  -------  -------
github.com/mountain-reverie/playwright-ci-go                                       73.85%   76.89%   +3.04%
                                                                          total:   73.85%   76.89%   +3.04%

[Copilot]

Pull request overview

Copilot reviewed 19 out of 21 changed files in this pull request and generated no new comments.

Suppressed comments (2)

imagetag_test.go:111

• Same issue here: the parallel subtest closes over the reused range variable test, which can cause cases to mix when t.Parallel() runs them concurrently. Shadow test := test inside the loop.

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()

			got, ok := versionFromBuildInfo(test.info, true)
			assert.Equal(t, test.ok, ok)
			assert.Equal(t, test.want, got)
		})

imagetag_test.go:36

• The subtest captures the range variable test while calling t.Parallel(). In Go, the range variable is reused, so parallel subtests can read the wrong case values and become flaky. Shadow the loop variable inside the loop before starting the subtest.

This issue also appears on line 104 of the same file.

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			t.Parallel()

			got, ok := playwrightGoTagLine(test.version)
			assert.Equal(t, test.ok, ok)
			assert.Equal(t, test.want, got)
		})