| // Copyright 2020 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Package regtest provides a framework for writing gopls regression tests. |
| // |
| // User reported regressions are often expressed in terms of editor |
| // interactions. For example: "When I open my editor in this directory, |
| // navigate to this file, and change this line, I get a diagnostic that doesn't |
| // make sense". In these cases reproducing, diagnosing, and writing a test to |
| // protect against this regression can be difficult. |
| // |
| // The regtest package provides an API for developers to express these types of |
| // user interactions in ordinary Go tests, validate them, and run them in a |
| // variety of execution modes (see gopls/doc/daemon.md for more information on |
| // execution modes). This is achieved roughly as follows: |
| // - the Runner type starts and connects to a gopls instance for each |
| // configured execution mode. |
| // - the Env type provides a collection of resources to use in writing tests |
| // (for example a temporary working directory and fake text editor) |
| // - user interactions with these resources are scripted using test wrappers |
| // around the API provided by the golang.org/x/tools/internal/lsp/fake |
| // package. |
| // |
| // Regressions are expressed in terms of Expectations, which at a high level |
| // are conditions that we expect to be met (or not to be met) at some point |
| // after performing the interactions in the test. This is necessary because the |
| // LSP is by construction asynchronous: both client and server can send |
| // each other notifications without formal acknowledgement that they have been |
| // fully processed. |
| // |
| // Simple Expectations may be combined to match specific conditions reported by |
| // the user. In the example above, a regtest validating that the user-reported |
| // bug had been fixed would "expect" that the editor never displays the |
| // confusing diagnostic. |
| package regtest |
