fix(core): unreadable interval_ms

[thomasqueirozb]

Summary

Make interval_ms readable from VRL

Vector configuration

sources:
  s0:
    type: static_metrics
    interval_secs: 1
    metrics:
      - name: response_time
        kind: incremental
        value:
          counter:
            value: 1
        tags: {}



transforms:
  t0:
    type: remap
    inputs:
      - s0
    source: |-
      .tags.exists_in_t0_start = to_string(exists(.interval_ms)) # true
      .tags.original_interval_ms = to_string!(.interval_ms) # 1000
      del(.interval_ms)
      .tags.exists_in_t0_end = to_string(exists(.interval_ms)) # false
  t1:
    type: remap
    inputs:
      - t0
    source: |-
      .tags.exists_in_t1_start = to_string(exists(.interval_ms)) # false
      .interval_ms = 666
      .tags.exists_in_t1_end = to_string(exists(.interval_ms)) # true
  t2:
    type: remap
    inputs:
      - t1
    source: |-
      .tags.exists_in_t2_start = to_string(exists(.interval_ms)) # true
      .tags.last_interval_ms = to_string!(.interval_ms) # 666


sinks:
  console:
    type: console
    inputs:
      - t2
    target: stdout
    encoding:
      codec: json
      json:
        pretty: true

How did you test this PR?

Ran the vector config, output should look something like this:

{
  "name": "response_time",
  "namespace": "static",
  "tags": {
    "exists_in_t0_end": "false",
    "exists_in_t0_start": "true",
    "exists_in_t1_end": "true",
    "exists_in_t1_start": "false",
    "exists_in_t2_start": "true",
    "last_interval_ms": "666",
    "original_interval_ms": "1000"
  },
  "timestamp": "2025-07-14T13:23:48.976670Z",
  "interval_ms": 666,
  "kind": "incremental",
  "counter": {
    "value": 1.0
  }
}

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

Closes: #23358
Related: #23221
Caused by: #23217

[datadog-vectordotdev]

Datadog Report

Branch report: fix-unreadable-interval-ms
Commit report: d1c772c
Test service: vector

✅ 0 Failed, 591 Passed, 0 Skipped, 4m 7.63s Total Time

[Copilot]

Pull Request Overview

This PR refactors how metric properties are populated in precompute_metric_value and adds support for exposing interval_ms in VRL, including updates to tests.

• Refactored property insertion to use a MetricProperty helper struct for cleaner logic.
• Added interval_ms as a first‐class metric property in both code and tests.

Comments suppressed due to low confidence (2)

lib/vector-core/src/event/vrl_target.rs:557

• [nitpick] Consider renaming the set field to something more descriptive like inserted or populated to clearly convey its purpose.

        set: bool,

lib/vector-core/src/event/vrl_target.rs:587

• Add a test case for when metric.interval_ms is None and requested in VRL to verify that the field is correctly omitted or handled.

        MetricProperty::new("interval_ms", |metric| metric.interval_ms().map(Into::into));

[pront]

is this https://github.com/vectordotdev/vector/pull/23361/checks?check_run_id=45926250836 an old result?