> On Sep 22, 2016, at 17:27, Aki Sasaki <asas...@mozilla.com> wrote: > > If we compile locally before testing in automation, we're no longer testing > the same bits that we're going to be shipping. That's a major change in > direction, and one that may have significant consequences.
We would only compile tests in test jobs: the binaries we ship to users would be downloaded from a build job. > > An additional historical reason for keeping development tools off test > machines: we once shipped a new runtime dependency that we didn't detect > because the test machines all had development environments. Users on that > platform were unable to run Firefox without installing a 3rd party library. It would be easy to add a test that verifies shared library dependencies against a whitelist. I'm, uh, kinda surprised we don't have that already. > > I very much agree with the goal of simplifying and streamlining how we run > tests. I think we do have to keep the above in mind when we go about that > simplification. > > >> On Thu, Sep 22, 2016 at 3:54 PM, Gregory Szorc <g...@mozilla.com> wrote: >> On Thu, Sep 22, 2016 at 2:49 PM, Nicholas Alexander <nalexan...@mozilla.com> >> wrote: >> >> > >> > >> > On Thu, Sep 22, 2016 at 1:20 PM, Gregory Szorc <g...@mozilla.com> wrote: >> > >> >> For years it has been a common pattern for local builds and Firefox >> >> automation to copy test files to the object directory (or some other >> >> staging area) and run them from there. This creates several >> >> inefficiencies: >> >> >> >> * The build system must symlink or copy thousands of test related files >> >> during the build >> >> * Running tests requires checking if test files in the objdir are up to >> >> date (can add significant latency to the edit-test loop) >> >> * Builds in automation must create and upload archives containing >> >> thousands of test files >> >> * This makes it harder to skip build jobs if all that has changed is a >> >> test file >> >> * Test jobs in automation must download and extract archives containing >> >> test files >> >> * Test jobs in automation typically don't have access to a full source >> >> checkout and can't easily piggyback on existing infrastructure (such as >> >> mach commands, vendored Python packages, etc). This leads to wheel >> >> reinvention and inconsistency between local dev environments and >> >> automation. >> >> >> >> The historical reasons for doing things this way were valid. But with >> >> moz.build, other improvements to the build system, automation scheduling >> >> and configuration living in-tree, and better scaling of Mercurial in >> >> automation, these historical reasons are largely no longer valid. >> >> >> >> Going forward, I'm requesting we change our policy regarding tests and >> >> automation to be source checkout first. This means: >> >> >> >> * Tests should be designed to run from a source checkout with minimal >> >> "build" actions required (no file copying/symlinking, no preprocessing >> >> into >> >> a new file, etc) >> >> * Automation should run everything from a source checkout (as opposed to >> >> downloading archives containing files derived from source checkouts) >> >> >> >> Does anyone have any concerns or objections to this? >> >> >> > >> > This only makes sense for a subset of our harnesses. Tests that need to >> > be compiled (gtest?, Android unit and Robocop tests) can never achieve >> > this. So as long as we're clear that we want to remove preprocessing and >> > special mozharness-foo to work around packaging tests but we're not pushing >> > *everything* to source-only, I'm good. >> > >> >> The goal is to reduce the amount of work needed to run tests. You are >> correct that compiled tests inherently need a build step to run them and we >> can't simply run them from a source checkout. >> >> That being said, it isn't out of the question to defer the compilation of >> these tests to test jobs: the build job delays execution of nearly all >> tests and making the build job faster by moving work out of that job could >> make end-to-end times faster, even if we're doing extra work in individual >> test jobs (that have to compile tests). Historically, we didn't have a >> compiler available on test machines. But with TaskCluster+Docker and >> tooltool, it is much easier to put needed files on testers. So compiling >> tests on test machines is something we should consider. >> _______________________________________________ >> tools mailing list >> to...@lists.mozilla.org >> https://lists.mozilla.org/listinfo/tools >
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