VS Code support for VRL (Vector Remap Language), the transformation
language used by Vector.
What it does today
- Diagnostics from the real compiler. The
vrl crate is compiled to
WebAssembly and shipped inside the extension, so what gets underlined in the
editor is what vector validate would reject — not a regex approximation.
It runs as you type, the compiler's notes and labels come through as related
information, and documented error codes link to
errors.vrl.dev.
- Hover, completion and signature help, generated from the compiler. Hover
a function for its signature, return type, whether the call can fail, its
parameters and its examples. Completion lists every function, marks the
fallible ones and expands into a call with tabstops — closure included for
for_each and friends — and after a . it offers the event paths this file
already uses. Signature help follows the cursor from one argument to the
next, named arguments included.
- Run a program on a sample event. Put
program.vrl.sample.json next to
program.vrl and VRL: Run on sample event compiles the program, runs it on
that event and opens the result beside the source. The sample also types the
program: .message is a string because the sample says so, so the "this
might fail" noise goes away and a misspelled field starts being caught.
- Syntax highlighting built for the constructs that actually show up in
production parsers: quoted path segments (
."@timestamp"), metadata paths
(%vector.ingest_timestamp), regex (r'…'), raw strings (s'…'),
timestamps (t'…'), the fallible-call ! told apart from negation, and
error destructuring (x, err = parse_json(.message)).
- Highlighting inside Vector configs: a
source: block scalar in a YAML
config, or a source = '''…''' string in a TOML one, is coloured as VRL.
- Snippets for the recurring shapes:
pjson, psyslog, pkv, pgrok,
pregex, ptime, coerce, foreach, mapvalues, ecs, abortif,
ifelse, ifmatch, iferr. Each one is compiled by the test suite, so a
snippet cannot expand into code the compiler rejects.
Which VRL
The extension tracks the vrl crate 0.35.0, the version Vector 0.58.0
depends on, and shows it in the status bar. A mismatch with the Vector you run
in production is the usual source of disagreement between an editor and a
deployment, so it is worth having on screen.
What it does not do yet
- With no sample event, the compiler is told nothing about the shape of your
events, so
parse_json(.message) is reported as fallible even when you know
.message is a string. A sample fixes the typing; it cannot make a function
that fails on valid input infallible.
- Diagnostics, hover and completion apply to
.vrl files. VRL embedded in a
Vector config is highlighted but not yet compiled.
- One sample event per program, not a set of them.
- Completion does not add the
! of a fallible call for you. Asserting turns
a handled error into an aborted program, and that is your decision to make.
Licence
MIT. The compiler inside it is the vrl crate, which is MPL-2.0 and is
consumed unmodified; its source is at https://github.com/vectordotdev/vrl
under the pinned tag. The terms of everything compiled into the WebAssembly
module ship with the extension, in THIRD-PARTY-NOTICES.md.
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