1
0
mirror of https://github.com/golang/go synced 2024-11-18 19:44:46 -07:00
Commit Graph

28 Commits

Author SHA1 Message Date
Ian Cottrell
80f63e2b9b internal/lsp: rewrite the stats using the newer telemetry features
This allows us to reduce the handler interface and delete the telemetry handler.
It is also safer and faster, and can be easily disabled along with the rest of
the telemetry system.

Change-Id: Ia4961d7f2e374f7dc22360d6a4020a065bfeae6f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225957
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2020-03-31 00:50:33 +00:00
Ian Cottrell
8dcfad9e01 internal/telemetry: switch metrics to use the event system
Change-Id: If036530ffe47e7df925bcf6592f664d6020a3d65
Reviewed-on: https://go-review.googlesource.com/c/tools/+/223997
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2020-03-23 14:44:30 +00:00
Rob Findley
9a0fabac01 internal/lsp: fix errors found by staticcheck
While experimenting with different static analysis on x/tools, I noticed
that there are many actionable diagnostics found by staticcheck. Fix the
ones that were not false positives.

Change-Id: I0b68cf1f636b57b557db879fad84fff9b7237a89
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222248
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2020-03-19 19:20:54 +00:00
Ian Cottrell
540150da73 internal/telemetry: add type safe tag keys
This changes the way keys work, there is still a single internal key
implementation for performance reasons, but the public interface is a set of key
implementations that have type safe Of and Get methods.
This also hides the implemenation of Tag so that we can modify the storage form
and find a more efficient storage if needed.

Change-Id: I6a39cc75c2824c6a92e52d59f16e82e876f16e9c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/223137
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
2020-03-18 13:29:43 +00:00
Ian Cottrell
04208b9e8a internal/lsp: move the telemetry package
Move the lsp specific telemetry package that just declares the labels under the
debug package and call it tag, to make all the usages much more readable.

Change-Id: Ic89b3408dd3b8b3d914cc69d81f41b8919aaf424
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222850
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
2020-03-18 13:22:49 +00:00
Rob Findley
30fd94b347 internal/lsp/lsprpc: expose configuration for auto-started daemon
Three new flags are added to the serve command, and threaded through to
the LSP forwarder:
 -remote.listen.timeout: -listen.timeout for the auto-started daemon
 -remote.debug: -debug for the auto-started daemon
 -remote.logfile: -logfile for the auto-started daemon

As part of this change, no longer enable debugging the daemon by
default.

Notably none of this configuration affects serving, so modifying this
configuration has been chosen not to change the path to the automatic
daemon. In other words, this configuration has effect only for the
forwarder process that starts the daemon: all others will connect to the
daemon and inherit whatever configuration it had at startup. This should
be OK, because in the common case this configuration should be static
across all clients (e.g., many Vim sessions all sharing the same
.vimrc).

Exposing this configuration made the signature of lsprpc.NewForwarder
a bit hard to understand, so I decided to go ahead and switch to a
variadic options pattern for initializing both the Forwarder and
StreamServer, the latter just for consistency with the Forwarder.

Updates golang/go#34111

Change-Id: Iefb71e337befe08b23e451477d19fd57e69f36c6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222670
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-03-12 19:43:16 +00:00
Rob Findley
bd435c612c internal/lsp/cmd: add an inspect verb
Add a new toplevel `inspect` verb to the gopls command, to expose the
internal state of a running gopls server. For now, this verb exposes a
single subcommand `sessions`, which lists some information about current
server sessions on a gopls daemon.

This can be used even if the debug server is not running, which will
become the default in a later CL.

Updates golang/go#34111

Change-Id: Ib7d654a659fa47280584f9a7301b952cbccc565a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222669
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-03-12 17:21:45 +00:00
Ian Cottrell
206ec5b82a internal/lsp: migrate telemetry to using the event package
Change-Id: Idc662385ed08bd62593ccd1d54afd3fa8c1a7d29
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222558
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2020-03-12 03:59:16 +00:00
Rob Findley
aa4048aca1 internal/lsp/lsprpc: don't connect to sockets owned by different users
When running gopls as a forwarder it attempts to forward the LSP to a
remote daemon. On posix systems, by default this uses a unix domain
socket at a predictable filesystem location.

As an extra precaution, attempt to verify that the remote socket is in
fact owned by the current user.

Also, change the default TCP listen address used on windows to bind to
localhost.

Updates golang/go#34111

Change-Id: Ib24886d290089a773851c5439586c3ddc9eb797d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222246
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-03-09 18:08:59 +00:00
Rob Findley
d1d1f200c6 internal/lsp/lsprpc: use Setsid on POSIX GOOSes, to avoid SIGTERMs
When the gopls daemon is automatically managed (-remote=auto), it will
be started by one of the forwarder gopls processes that was in turn
started by the editor. By default, this puts it in the same process
group as the forwarder gopls.

Some editors (at least Vim) send SIGTERM to the process groups of
sidecar processes when exiting. This can cause the gopls daemon to
terminate, thereby losing state.

Rather than ignore SIGTERM (which is bound to be editor dependent
anyway), let's just put the gopls daemon in a separate session.

Updates golang/go#34111

Change-Id: I71386fb54b8c2efe1c565f59763f46693a7d48b0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221220
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-03-05 21:44:44 +00:00
Ian Cottrell
4183ba16a9 internal/lsp: move the debug.Instance onto the Context
This allows us to register a telemetry exporter that works with mulitple active
debug instances.
It also means we don't have to store the debug information in our other objects.

Change-Id: I9a9d5b0407c3352b6eaff80fb2c434ca33f4e397
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221558
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2020-03-03 22:54:53 +00:00
Pontus Leitzler
066e0c0245 internal/lsp/lsprpc: use localhost for remote gopls debug interface
When using the experimental feature where gopls runs as deamon, the
remote is spawned with debug enabled. It currently exposes the debug
interface to all network interfaces. This should be configurable in
the future, but until then we should at least keep it on the
localhost interface.

This change starts the debug on the local interface instead of all.

Updates golang/go#34111

Change-Id: I3184268dd434ae11ff5f8c3c57a229d22c158196
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221697
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2020-03-01 22:23:51 +00:00
Rob Findley
45849e8256 internal/lsp/lsprpc: wait for the handshake before running clientConn
By running the client connection before the forwarder-remote handshake
completes, we introduce a race in the TestDebugInfoLifecycle: the editor
may connect and initialize before the handshake, and assertions on the
debug state fail.

Requiring that the handshake complete before running the client
connection fixes this flakiness. It also seems like a good thing to
have the handshake complete before proceeding with any LSP.

Fixes golang/go#37444

Change-Id: I07187797b4759bcaf99f5b0a0b3cd7ac7de34f43
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220903
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2020-02-25 18:38:23 +00:00
Rob Findley
daf22849ce internal/lsp/lsprpc: add a 1m timeout to auto-started gopls
It would be bad behavior if a gopls forwarder process started the gopls
daemon and it stuck around indefinitely. Add an idle timeout by default
for the gopls daemon.

Updates golang/go#34111

Change-Id: I0408a1e6a3b89d862803ae5c439d6aa0d8ed9494
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220521
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-24 23:36:36 +00:00
Rob Findley
63caf62cea internal/lsp/lsprpc: clean up client session on disconnection
Gopls behavior on disconnection is currently somewhat undefined, because
it hasn't mattered when there was a single gopls session per binary
invocation. With golang/go#34111, this changes.

Checks are added to ensure clients and sessions are cleaned up when an LSP
connection closes. Also, normal client disconnection is differentiated
with the jsonrpc2.ErrDisconnected value.

Updates golang/go#34111

Change-Id: I74d48ad6dcfc30d11f7f751dcffb20c18a4cbaa3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220519
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-24 23:23:05 +00:00
Rob Findley
a208025ccb internal/lsp/lsprpc: automatically resolve and start the remote gopls
Most users will not want to manage their own gopls instance, but may
still want to benefit from using a shared instance.

This CL adds support for an 'auto' network type that can be encoded in
the -remote flag similarly to UDS (i.e. -remote="auto;uniqueid"). In
this mode, the actual remote address will be resolved automatically
based on the executing environment and unique identifier, and the remote
server will be started if it isn't already running.

Updates golang/go#34111

Change-Id: Ib62159765a108f3645f57709b8ff079b39dd6727
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220137
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-24 22:51:55 +00:00
Rob Findley
20f46356b3 internal/lsp/lsprpc: add a handshake between forwarder and remote
In the ideal future, users will have one or more gopls instances, each
serving potentially many LSP clients. In order to have any hope of
navigating this web, clients and servers must know about eachother.

To allow for such an exchange of information, this CL adds an additional
handler layer to the serving configured in the lsprpc package. For now,
forwarders just use this layer to execute a handshake with the LSP
server, communicating the location of their logs and debug addresses.

Updates golang/go#34111

Change-Id: Ic7432062c01a8bbd52fb4a058a95bbf5dc26baa3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220081
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-24 22:51:04 +00:00
Rob Findley
e02f5847d1 internal/lsp/debug: move all debug state onto the Instance
For testability, and to support the exchange of debug information across
Forwarder and server, it is helpful to encapsulate all debug information
on the instance object.

This CL moves all state in the debug package into a new 'State' type,
that is added as a field on the debug.Instance. While doing so, common
functionality for object collections is factored out into the objset
helper type.

Also add two new debug object types: Client and Server. These aren't yet
used, but will be in a later CL (and frankly it was easier to leave them
in this CL than to more carefully rewrite history...).

Updates golang/go#34111

Change-Id: Ib809cd14cb957b41a9bcbd94a991f804531a76ea
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220078
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-24 22:50:47 +00:00
Rob Findley
c4d4ea9c79 internal/lsp/cache: return concrete types where possible
For testability, and to allow the exchange of debug information when
forwarding the LSP, it will be necessary to access debug information
stored in cache objects. This is cumbersome to do if our constructors
return source interfaces rather than concrete types.

This CL changes cache.New and (*Cache).NewSession to return concrete
types. This required removing NewSession from source.Cache. I would
argue that this makes sense from a philosophical perspective: everything
in the source package operates in a context where the Session and Cache
already exist.

Updates golang/go#34111

Change-Id: I01721db827d51117f9479f1544b15cedae0c5921
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220077
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2020-02-19 18:42:16 +00:00
Rob Findley
5fb17a1e7b internal/jsonrpc2: support serving over unix domain sockets
For tests (and perhaps later, for daemon discovery), unix domain sockets
offer advantages over TCP: we can know the exact socket address that will be
used when starting a server subprocess. They also offer performance and
security advantages over TCP, and were specifically requested on
golang.org/issues/34111.

This CL adds support for listening on UDS, and uses this to implement an
additional regtest environment mode that starts up an external process.
This mode is disabled by default, but may be enabled by the
-enable_gopls_subprocess_tests.

The regtest TestMain may be hijacked to instead run as gopls, if a
special environment variable is set. This allows the the test runner to
start a separate process by using os.Argv[0]. The -gopls_test_binary
flag may be used to point tests at a separate gopls binary.

Updates golang/go#36879
Updates golang/go#34111

Change-Id: I1cfdf55040e81ffa69a6726878a96529e5522e82
Reviewed-on: https://go-review.googlesource.com/c/tools/+/218839
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-19 16:14:01 +00:00
Rob Findley
741f65b509 internal/lsp/lsprpc: add a forwarder handler
Add a forwarder handler that alters messages before forwarding, for now,
it just intercepts the "exit" message.

Also, make it easier to write regression tests for a shared gopls
instance, by adding a helper that instantiates two connected
environments, and only runs in the shared execution modes.

Updates golang/go#36879
Updates golang/go#34111

Change-Id: I7673f72ab71b5c7fd6ad65d274c15132a942e06a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/218778
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-19 15:38:09 +00:00
Rob Findley
b320d3a0f5 internal/jsonrpc2/servertest: support both TCP and pipe connection
Update the servertest package to support connecting to a jsonrpc2 server
using either TCP or io.Pipes. The latter is provided so that regtests
can more accurately mimic the current gopls execution mode, where gopls
is run as a sidecar and communicated with via a pipe.

Updates golang/go#36879

Change-Id: I0e14ed0e628333ba2cc7b088009f1887fcaa82a5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/218777
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-16 19:22:41 +00:00
Rob Findley
88be01311a internal/jsonrpc2: fix races in cancellation
We had a deadlock in cases where a request was cancelled (1) after being
written to the stream, but (2) before a response was received. This
resulted in the request ID being removed from the pending map while the
server has the request, after which point the server response would hang
in Conn.Run trying to send to a nil channel.

After fixing this nil send there was still a race: it was possible that
Conn.Run could get the pending request, and Conn.Call would select
ctx.Done before Conn.Run could send to the response channel, again
resulting in a blocking send. Fix this by adding a buffer to the
response channel.

The response channel management is also made less forgiving, because we
should be able to reason precisely about how many sends and receives
will occur:
 + Don't close the response channel after sending a response: there
   should only be one recipient.
 + Don't delete the ID from pending map twice: it should only be cleaned
   up by Conn.Call.

Cancellation tests in the lsprpc package are updated to exercise the
race conditions.

Fixes golang/go#37159

Change-Id: Ie3207442ea910f79247b18d8647fd52f39fb15db
Reviewed-on: https://go-review.googlesource.com/c/tools/+/219126
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-14 14:43:24 +00:00
Rob Findley
0fd2d649e6 internal/lsp/lsprpc: add an LSP forwarder and regtest environment
Add a new Forwarder type to the lsprpc package, which implements the
jsonrpc2.StreamServer interface. This will be used to establish some
parity in the implementation of shared and singleton gopls servers.

Much more testing is needed, as is handling for the many edge cases
around forwarding the LSP, but since this is functionally equivalent to
TCP forwarding (and the -remote flag was already broken), I went ahead
and used the Forwarder to replace the forward method in the serve
command. This means that we can now use the combination of -listen and
-remote to chain together gopls servers... not that there's any reason
to do this.

Also, wrap the new regression tests with a focus on expressiveness when
testing the happy path, as well as parameterizing them so that they can
be run against different client/server execution environments. This
started to be sizable enough to warrant moving them to a separate
regtest package. The lsprpc package tests will instead focus on unit
testing the client-server binding logic.

Updates golang/go#36879
Updates golang/go#34111

Change-Id: Ib98131a58aabc69299845d2ecefceccfc1199574
Reviewed-on: https://go-review.googlesource.com/c/tools/+/218698
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-14 14:21:06 +00:00
Rob Findley
9fbd0ccf67 internal/lsp/lsprpc: add test for definition outside of workspace
Add regression tests for GoToDefinition. In particular, exercise the
panic from golang/go#37045.

Updates golang/go#37045
Updates golang/go#36879

Change-Id: I67b562acd293f47907de0435c14b62c1a22cf2ee
Reviewed-on: https://go-review.googlesource.com/c/tools/+/218322
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2020-02-10 17:53:45 +00:00
Rob Findley
babff93c04 internal/lsp/lsprpc: add test for empty diagnostics in deleted files
Add a test for the bug reported in golang/go#37049: we are missing empty
diagnostics for deleted files. Doing this involved added a missing
RemoveFile method on the fake.Watcher type.

Skip the test for now, as it is failing.

Updates golang/go#37049
Updates golang/go#36879

Change-Id: Ib3b6907455cc44a2e6af00c2254aa444e9480749
Reviewed-on: https://go-review.googlesource.com/c/tools/+/218278
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2020-02-10 17:44:40 +00:00
Rob Findley
f9587291b6 internal/lsp/fake: add fakes for testing editor interaction
A lot of bug reports originating from LSP clients are related to either
the timing or sequence of editor interactions with gopls (or at least
they're originally reported this way). For example: "when I open a
package and then create a new file, I lose diagnostics for existing
files".  These conditions are often hard to reproduce, and to isolate as
either a gopls bug or a bug in the editor.

Right now we're relying on govim integration tests to catch these
regressions, but it's important to also have a testing framework that
can exercise this functionality in-process.  As a starting point this CL
adds test fakes that implement a high level API for scripting editor
interactions. A fake workspace can be used to sandbox file operations; a
fake editor provides an interface for text editing operations; a fake
LSP client can be used to connect the fake editor to a gopls instance.
Some tests are added to the lsprpc package to demonstrate the API.

The primary goal of these fakes should be to simulate an client that
complies to the LSP spec. Put another way: if we have a bug report that
we can't reproduce with our regression tests, it should either be a bug
in our test fakes or a bug in the LSP client originating the report.

I did my best to comply with the spec in this implementation, but it
will certainly develop as we write more tests. We will also need to add
to the editor API in the future for testing more language features.

Updates golang/go#36879
Updates golang/go#34111

Change-Id: Ib81188683a7066184b8a254275ed5525191a2d68
Reviewed-on: https://go-review.googlesource.com/c/tools/+/217598
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
2020-02-10 17:44:19 +00:00
Rob Findley
c29062fe1d internal/lsp: refactor LSP server instantiation
Previously, the process of instantiating and running the LSP server was
sharded across the lsp, protocol, and cmd packages, and this resulted in
some APIs that are hard to work with. For example, it's hard to guess
the difference between lsp.NewClientServer, lsp.NewServer,
protocol.NewServer (which returns a client), and protocol.NewClient
(which returns a server).

This change reorganizes Server instantiation as follows:

 + The lsp.Server is now purely an implementation of the protocol.Server
   interface. It is no longer responsible for installing itself into the
   jsonrpc2 Stream, nor for running itself.

 + A new package 'lsprpc' is added, to implement the logic of binding an
   incoming connection to an LSP server session. This is put in a
   separate package for lack of a clear home: it didn't really
   philosophically belong in any of the lsp, cmd, or protocol packages.
   We can perhaps move it to cmd in the future, but I'd like to keep it
   as a separate package while I develop request forwarding.

   simplified import graph:

    jsonrpc2 ⭠ lsprpc ⭠ cmd
               ⭩           ⭦
            lsp           (t.b.d. client tests)
           ⭩   ⭨
     protocol  source

 + The jsonrpc2 package is extended to have a minimal API for running a
   'StreamServer': something analogous to an HTTP server that listens
   for new connections and delegates to a handler (but we couldn't use
   the word 'Handler' for this delegate as it was already taken).

After these changes, I hope that the concerns of "serving the LSP",
"serving jsonrpc2", and "installing the LSP on jsonrpc2" are more
logically organized, though one legitimate criticism is that the word
'Server' is still heavily overloaded.

This change prepares a subsequent change which hijacks the jsonrpc2
connection when forwarding messages to a shared gopls instance.

To test this change, the following improvements are made:

 + A servertest package is added to make it easier to run a test against
   an in-process jsonrpc2 server. For now, this uses TCP but it could
   easily be modified to use io.Pipe.

 + cmd tests are updated to use the servertest package. Unfortunately it
   wasn't yet possible to eliminate the concept of `remote=internal` in
   favor of just using multiple sessions, because view initialization
   involves calling both `go env` and `packages.Load`, which slow down
   session startup significantly. See also golang.org/issue/35968.

   Instead, the syntax for `-remote=internal` is modified to be
   `-remote=internal@127.0.0.1:12345`.

 + An additional test for request cancellation is added for the
   sessionserver package. This test uncovered a bug: when calling
   Canceller.Cancel, we were using id rather than &id, which resulted in
   incorrect json serialization (as only the pointer receiver implements
   the json.Marshaller interface).

Updates golang/go#34111

Change-Id: I75c219df634348cdf53a9e57839b98588311a9ef
Reviewed-on: https://go-review.googlesource.com/c/tools/+/215742
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2020-02-06 23:12:37 +00:00