fix(debugger): initialize lastCaptureNs to ensure first probe hit is captured

[watson]

What does this PR do?

Initialize a probes lastCaptureNs to BigInt(Number.MIN_SAFE_INTEGER), ensuring the first probe hit always passes the sampling check regardless of when it occurs.

Motivation

When a probe is added with any sampling rate, the first probe hit could be incorrectly skipped if it occurred within the sampling interval after process start.

This happened because lastCaptureNs was initialized to 0n, causing the sampling check start - probe.lastCaptureNs < probe.nsBetweenSampling to evaluate to true when the process had been running for less time than the sampling interval.

For example:

• At 10 samples/sec: first hit skipped if within first 100ms
• At 5 samples/sec: first hit skipped if within first 200ms
• At 1 sample/sec: first hit skipped if within first 1 second
• At 0.5 samples/sec: first hit skipped if within first 2 seconds

[github-actions]

Overall package size

Self size: 13.6 MB
Deduped: 113.8 MB
No deduping: 128.82 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | @datadog/libdatadog | 0.7.0 | 35.02 MB | 35.02 MB | | @datadog/native-appsec | 10.3.0 | 20.73 MB | 20.74 MB | | @datadog/pprof | 5.12.0 | 11.19 MB | 11.57 MB | | @datadog/native-iast-taint-tracking | 4.1.0 | 9.01 MB | 9.02 MB | | @opentelemetry/resources | 1.30.1 | 557.67 kB | 7.71 MB | | @opentelemetry/core | 1.30.1 | 908.66 kB | 7.16 MB | | protobufjs | 7.5.4 | 2.95 MB | 5.83 MB | | @datadog/wasm-js-rewriter | 5.0.1 | 2.82 MB | 3.53 MB | | @datadog/native-metrics | 3.1.1 | 1.02 MB | 1.43 MB | | @opentelemetry/api-logs | 0.208.0 | 199.48 kB | 1.42 MB | | @opentelemetry/api | 1.9.0 | 1.22 MB | 1.22 MB | | jsonpath-plus | 10.3.0 | 617.18 kB | 1.08 MB | | import-in-the-middle | 1.15.0 | 127.66 kB | 856.24 kB | | lru-cache | 10.4.3 | 804.3 kB | 804.3 kB | | @datadog/openfeature-node-server | 0.2.0 | 118.51 kB | 437.19 kB | | opentracing | 0.14.7 | 194.81 kB | 194.81 kB | | source-map | 0.7.6 | 185.63 kB | 185.63 kB | | pprof-format | 2.2.1 | 163.06 kB | 163.06 kB | | @datadog/sketches-js | 2.1.1 | 109.9 kB | 109.9 kB | | @isaacs/ttlcache | 2.1.3 | 90.79 kB | 90.79 kB | | lodash.sortby | 4.7.0 | 75.76 kB | 75.76 kB | | ignore | 7.0.5 | 63.38 kB | 63.38 kB | | istanbul-lib-coverage | 3.2.2 | 34.37 kB | 34.37 kB | | rfdc | 1.4.1 | 27.15 kB | 27.15 kB | | dc-polyfill | 0.1.10 | 26.73 kB | 26.73 kB | | tlhunter-sorted-set | 0.1.0 | 24.94 kB | 24.94 kB | | shell-quote | 1.8.3 | 23.74 kB | 23.74 kB | | limiter | 1.1.5 | 23.17 kB | 23.17 kB | | retry | 0.13.1 | 18.85 kB | 18.85 kB | | semifies | 1.0.0 | 15.84 kB | 15.84 kB | | jest-docblock | 29.7.0 | 8.99 kB | 12.76 kB | | crypto-randomuuid | 1.0.0 | 11.18 kB | 11.18 kB | | ttl-set | 1.0.0 | 4.61 kB | 9.69 kB | | mutexify | 1.4.0 | 5.71 kB | 8.74 kB | | path-to-regexp | 0.1.12 | 6.6 kB | 6.6 kB | | module-details-from-path | 1.0.4 | 3.96 kB | 3.96 kB | | escape-string-regexp | 5.0.0 | 3.66 kB | 3.66 kB |

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}

[watson]

• fix(debugger): initialize lastCaptureNs to ensure first probe hit is captured #7042 👈 (View in Graphite)
• master

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.83%. Comparing base (581b163) to head (286e68c).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #7042   +/-   ##
=======================================
  Coverage   84.83%   84.83%           
=======================================
  Files         517      517           
  Lines       22050    22050           
=======================================
  Hits        18707    18707           
  Misses       3343     3343           

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[pr-commenter]

Benchmarks

Benchmark execution time: 2025-12-06 10:19:44

Comparing candidate commit 286e68c in PR branch watson/ensure-first-capture-happens with baseline commit 581b163 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 288 metrics, 32 unstable metrics.