This option provides a new way of terminating the probing by
specifying a limit for the per-probe hit evaluation. When any
probe reaches the limit, the session removes the V8 breakpoints
and finishes with a `completed` terminal event rather than waiting
for the target to exit or timeout. This would be useful when we
provide a way to attach to and probe a running process in the future.
Signed-off-by: Joyee Cheung <joyeec9h3@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/63704
Refs: https://github.com/nodejs/node/issues/63646
Reviewed-By: Jan Martin <jan.krems@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
This addresses a few TODOs left from the initial implementation
around the error handling when the inspector session fails
mid-probe - for example because a probe expression terminates
the target, severs the inspector connection, or hangs the
evaluation. Before this patch, these failures would cause the
probe report to silently miss hits or hit the session timeout.
A consumer of these reports could not tell whether the
recorded hits were reliable or a partial trace cut short
by an inspector-side failure.
This patch surfaces those cases as a new `probe_failure` terminal
`error` event on the report, with best-effort attribution to the
implicated probe via `error.probe` and additional context on
`error.details`. Together with `probe_timeout`, it marks the
report as best-effort, and the probing process exits 1 in both
cases. `probe_target_exit` and clean `completed`/`miss` reports
continue to exit 0 because the recorded hits in those cases remain
ground truth, so tooling can use the exit code as a quick
trustworthiness signal. `error.message` now also contains
actionable recovery hints whereever possible.
The per-hit `error` is reshaped to `{ message, details? }`
so that the per-hit and terminal errors share a top-level shape.
Both fields are informative-only, only their top-level type is stable.
Signed-off-by: Joyee Cheung <joyeec9h3@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/63437
Refs: https://github.com/nodejs/node/pull/62713
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Jan Martin <jan.krems@gmail.com>
In probe mode, `--probe utils.js:10` can match multiple scripts
(e.g. `src/utils.js` and `lib/utils.js`) because the matcher uses
a path-separator-anchored URL suffix (similar to how e.g. gdb/lldb
behaves). Previously the report echoed only the user's request in
hit events, so a user seeing two hits at `utils.js:10` could not
tell which script each hit came from. In addition, previously
when the column was omitted we bound to 1 which was technically
different from how CDP binds omitted columns (to the first
executable column on the line).
This patch clarifies the semantics by tracking the scripts via
`Debugger.scriptParsed`, as recommended in the CDP docs, and
reports the actual execution location as `results[i].location`.
The same shape can be reused in the future for source maps or
additional events in attach mode.
This bumps the schema version because `target` is now
`{ suffix, line, column? }` instead of a positional array for
clarity. We picked `suffix` as the field name in case we
introduce other matching modes in the future. `column` is
omitted when the user did not supply one, and the actual
resolved column is reported in the hit event instead.
This patch also adds more tests for column-specific bindings,
multi-location resolution via require(cjs), and late script
binding via dynamic import(cjs) and require(esm).
Signed-off-by: Joyee Cheung <joyeec9h3@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/63286
Reviewed-By: Jan Martin <jan.krems@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Add a non-interactive probe mode to `node inspect` for inspecting
runtime values in a run-to-completion application. This allows
users to perform printf-style debugging without having to modify
the application code and clean up afterwards, it also supports
structured output to be consumed by tools.
Probe mode launches the application, sets one or more source
breakpoints, evaluates one expression at each hit, and prints a
single text or JSON report when execution ends.
Interface:
node inspect [--json] [--preview] [--timeout=<ms>] [--port=<port>]
--probe <file>:<line>[:<col>] --expr <expr> ...
[--] <script> [args...]
Example:
```js
// cli.js
let maxRSS = 0;
for (let i = 0; i < 2; i++) {
const { rss } = process.memoryUsage();
maxRSS = Math.max(maxRSS, rss);
}
```
```
$ node inspect --probe cli.js:5 --expr 'rss' cli.js
Hit 1 at cli.js:5
rss = 54935552
Hit 2 at cli.js:5
rss = 55083008
Completed
```
(Prettified JSON to fit in commit message restrictions).
```js
$ node inspect --json --probe cli.js:5 --expr 'rss' cli.js
{"v":1,"probes":[{"expr":"rss","target":["cli.js",5]}],
"results":[
{"probe":0,"event":"hit","hit":1,
"result":{"type":"number","value":55443456,
"description":"55443456"}},
{"probe":0,"event":"hit","hit":2,
"result":{"type":"number","value":55574528,
"description":"55574528"}},
{"event":"completed"}]}
```
Signed-off-by: Joyee Cheung <joyeec9h3@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/62713
Reviewed-By: Jan Martin <jan.krems@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Joyee Cheung