mirror of
https://github.com/matrix-org/dendrite
synced 2024-11-16 06:41:06 +01:00
90 lines
3.1 KiB
Markdown
90 lines
3.1 KiB
Markdown
# Code Style
|
|
|
|
We follow the standard Go style using gofmt, but with a few extra
|
|
considerations.
|
|
|
|
## Linters
|
|
|
|
We use `gometalinter` to run a number of linters, the exact list can be found
|
|
in [linter.json](linter.json). Some of these are slow and expensive to run, but
|
|
a subset can be found in [linter-fast.json](linter-fast.json) that run quickly
|
|
enough to be run as part of an IDE.
|
|
|
|
For rare cases where a linter is giving a spurious warning, it can be disabled
|
|
for that line or statement using a [comment directive](https://github.com/alecthomas/gometalinter#comment-directives), e.g.
|
|
`// nolint: gocyclo`. This should be used sparingly and only when its clear
|
|
that the lint warning is spurious.
|
|
|
|
The linters are vendored, and can be run using [scripts/find-lint.sh](scripts/find-lint.sh)
|
|
(see file for docs) or as part of a build/test/lint cycle using
|
|
[scripts/build-test-lint.sh](scripts/build-test-lint.sh).
|
|
|
|
|
|
## HTTP Error Handling
|
|
|
|
Unfortunately, converting errors into HTTP responses with the correct status
|
|
code and message can be done in a number of ways in golang:
|
|
|
|
1. Having functions return `JSONResponse` directly, which can then either set
|
|
it to an error response or a `200 OK`.
|
|
2. Have the HTTP handler try and cast error values to types that are handled
|
|
differently.
|
|
3. Have the HTTP handler call functions whose errors can only be interpreted
|
|
one way, for example if a `validate(...)` call returns an error then handler
|
|
knows to respond with a `400 Bad Request`.
|
|
|
|
We attempt to always use option #3, as it more naturally fits with the way that
|
|
golang generally does error handling. In particular, option #1 effectively
|
|
requires reinventing a new error handling scheme just for HTTP handlers.
|
|
|
|
|
|
## Line length
|
|
|
|
We strive for a line length of roughly 80 characters, though less than 100 is
|
|
acceptable if necessary. Longer lines are fine if there is nothing of interest
|
|
after the first 80-100 characters (e.g. long string literals).
|
|
|
|
|
|
## TODOs and FIXMEs
|
|
|
|
The majority of TODOs and FIXMEs should have an associated tracking issue on
|
|
github. These can be added just before merging of the PR to master, and the
|
|
issue number should be added to the comment, e.g. `// TODO(#324): ...`
|
|
|
|
|
|
## Logging
|
|
|
|
We generally prefer to log with static log messages and include any dynamic
|
|
information in fields.
|
|
|
|
```golang
|
|
logger := util.GetLogger(ctx)
|
|
|
|
// Not recommended
|
|
logger.Infof("Finished processing keys for %s, number of keys %d", name, numKeys)
|
|
|
|
// Recommended
|
|
logger.WithFields(logrus.Fields{
|
|
"numberOfKeys": numKeys,
|
|
"entityName": name,
|
|
}).Info("Finished processing keys")
|
|
```
|
|
|
|
This is useful when logging to systems that natively understand log fields, as
|
|
it allows people to search and process the fields without having to parse the
|
|
log message.
|
|
|
|
|
|
## Visual Studio Code
|
|
|
|
If you use VSCode then the following is an example of a workspace setting that
|
|
sets up linting correctly:
|
|
|
|
```json
|
|
{
|
|
"go.gopath": "${workspaceRoot}:${workspaceRoot}/vendor",
|
|
"go.lintOnSave": "workspace",
|
|
"go.lintTool": "gometalinter",
|
|
"go.lintFlags": ["--config=linter-fast.json", "--concurrency=5"]
|
|
}
|
|
```
|