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Use Effect Schema for Windows process diagnostics #3600

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f3da91a
Use Effect Schema for Windows process diagnostics
cursoragent Jun 29, 2026
0bb0f53
Format Windows process diagnostics parser
cursoragent Jun 29, 2026
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94 changes: 93 additions & 1 deletion apps/server/src/diagnostics/ProcessDiagnostics.test.ts
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
import { describe, expect, it } from "@effect/vitest";
import { assert, describe, expect, it } from "@effect/vitest";
import * as DateTime from "effect/DateTime";
import * as Effect from "effect/Effect";
import * as Layer from "effect/Layer";
Expand Down Expand Up @@ -67,6 +67,98 @@ describe("ProcessDiagnostics", () => {
}),
);

it.effect("parses Windows CIM JSON process rows", () =>
Effect.sync(() => {
const rows = ProcessDiagnostics.parseWindowsProcessRows(`[
{
"ProcessId": 10,
"ParentProcessId": 1,
"Name": "node.exe",
"CommandLine": "node server.js",
"Status": "Running",
"WorkingSetSize": 4096,
"PercentProcessorTime": 12.5
},
{
"ProcessId": "invalid",
"ParentProcessId": 10,
"Name": "ignored.exe"
},
{
"ProcessId": 11,
"ParentProcessId": 10,
"Name": "agent.exe",
"CommandLine": null,
"Status": null,
"WorkingSetSize": -128,
"PercentProcessorTime": -1
}
]`);

assert.deepStrictEqual(rows, [
{
pid: 10,
ppid: 1,
pgid: null,
status: "Running",
cpuPercent: 12.5,
rssBytes: 4096,
elapsed: "",
command: "node server.js",
},
{
pid: 11,
ppid: 10,
pgid: null,
status: "Live",
cpuPercent: 0,
rssBytes: 0,
elapsed: "",
command: "agent.exe",
},
]);
}),
);

it.effect("parses single Windows CIM JSON process objects", () =>
Effect.sync(() => {
const rows = ProcessDiagnostics.parseWindowsProcessRows(`{
"ProcessId": 42,
"ParentProcessId": 10,
"Name": "agent.exe",
"CommandLine": "",
"WorkingSetSize": 2048,
"PercentProcessorTime": 5
}`);

assert.deepStrictEqual(rows, [
{
pid: 42,
ppid: 10,
pgid: null,
status: "Live",
cpuPercent: 5,
rssBytes: 2048,
elapsed: "",
command: "agent.exe",
},
]);
}),
);

it.effect("ignores malformed Windows CIM JSON output", () =>
Effect.sync(() => {
assert.deepStrictEqual(ProcessDiagnostics.parseWindowsProcessRows("{not json"), []);
assert.deepStrictEqual(
ProcessDiagnostics.parseWindowsProcessRows(`{
"ProcessId": 42,
"Name": "missing-parent.exe"
}`),
[],
);
}),
);

it.effect("aggregates only descendants of the server process", () =>
Effect.sync(() => {
const diagnostics = ProcessDiagnostics.aggregateProcessDiagnostics({
Expand Down
102 changes: 59 additions & 43 deletions apps/server/src/diagnostics/ProcessDiagnostics.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@ export interface ProcessRow {
readonly command: string;
}

const PROCESS_QUERY_TIMEOUT_MS = 1_000;
const PROCESS_QUERY_TIMEOUT = Duration.seconds(1);
const POSIX_PROCESS_QUERY_COMMAND = "pid=,ppid=,pgid=,stat=,pcpu=,rss=,etime=,command=";
const PROCESS_QUERY_MAX_OUTPUT_BYTES = 2 * 1024 * 1024;

Expand Down Expand Up @@ -121,6 +121,19 @@ const ProcessDiagnosticsError = Schema.Union([
type ProcessDiagnosticsError = typeof ProcessDiagnosticsError.Type;
const isProcessDiagnosticsError = Schema.is(ProcessDiagnosticsError);

const WindowsCimProcessRecord = Schema.Struct({
ProcessId: Schema.Number,
ParentProcessId: Schema.Number,
Name: Schema.optional(Schema.NullOr(Schema.String)),
CommandLine: Schema.optional(Schema.NullOr(Schema.String)),
Status: Schema.optional(Schema.NullOr(Schema.String)),
WorkingSetSize: Schema.optional(Schema.Number),
PercentProcessorTime: Schema.optional(Schema.Number),
});
type WindowsCimProcessRecord = typeof WindowsCimProcessRecord.Type;
const decodeWindowsProcessJson = Schema.decodeUnknownOption(Schema.fromJsonString(Schema.Json));
const decodeWindowsProcessRecord = Schema.decodeUnknownOption(WindowsCimProcessRecord);

function parsePositiveInt(value: string): number | null {
const parsed = Number.parseInt(value, 10);
return Number.isInteger(parsed) && parsed > 0 ? parsed : null;
Expand Down Expand Up @@ -201,51 +214,54 @@ export function parsePosixProcessRows(output: string): ReadonlyArray<ProcessRow>
return rows;
}

function normalizeWindowsProcessRow(value: unknown): ProcessRow | null {
if (typeof value !== "object" || value === null) return null;
const record = value as Record<string, unknown>;
const pid = typeof record.ProcessId === "number" ? record.ProcessId : null;
const ppid = typeof record.ParentProcessId === "number" ? record.ParentProcessId : null;
const commandLine =
typeof record.CommandLine === "string" && record.CommandLine.trim().length > 0
? record.CommandLine
: typeof record.Name === "string"
? record.Name
: null;
const workingSet =
typeof record.WorkingSetSize === "number" && Number.isFinite(record.WorkingSetSize)
? Math.max(0, Math.round(record.WorkingSetSize))
: 0;
const cpuPercent =
typeof record.PercentProcessorTime === "number" && Number.isFinite(record.PercentProcessorTime)
? Math.max(0, record.PercentProcessorTime)
: 0;

if (!pid || pid <= 0 || ppid === null || ppid < 0 || !commandLine) return null;
return {
pid,
ppid,
pgid: null,
status: typeof record.Status === "string" && record.Status.length > 0 ? record.Status : "Live",
cpuPercent,
rssBytes: workingSet,
elapsed: "",
command: commandLine,
};
function nonEmptyStringOption(value: string | null | undefined): Option.Option<string> {
return typeof value === "string" && value.trim().length > 0 ? Option.some(value) : Option.none();
}

function parseWindowsProcessRows(output: string): ReadonlyArray<ProcessRow> {
function normalizeWindowsProcessRow(value: unknown): Option.Option<ProcessRow> {
return Option.flatMap(decodeWindowsProcessRecord(value), (record: WindowsCimProcessRecord) => {

@macroscopeapp macroscopeapp Bot Jun 29, 2026

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🟡 Medium diagnostics/ProcessDiagnostics.ts:222

normalizeWindowsProcessRow runs the whole record through decodeWindowsProcessRecord, whose schema treats WorkingSetSize, PercentProcessorTime, and Status as typed optional fields. A record like { "ProcessId": 42, "ParentProcessId": 1, "Name": "node.exe", "WorkingSetSize": "4096" } previously produced a row with rssBytes: 0, but now decodeWindowsProcessRecord returns None because WorkingSetSize is a string, so the entire process row is silently dropped. Consider decoding only the required fields (ProcessId, ParentProcessId) strictly and reading the optional fields defensively, as the previous implementation did.

🚀 Reply "fix it for me" or copy this AI Prompt for your agent: 
In file @apps/server/src/diagnostics/ProcessDiagnostics.ts around line 222:

`normalizeWindowsProcessRow` runs the whole record through `decodeWindowsProcessRecord`, whose schema treats `WorkingSetSize`, `PercentProcessorTime`, and `Status` as typed optional fields. A record like `{ "ProcessId": 42, "ParentProcessId": 1, "Name": "node.exe", "WorkingSetSize": "4096" }` previously produced a row with `rssBytes: 0`, but now `decodeWindowsProcessRecord` returns `None` because `WorkingSetSize` is a string, so the entire process row is silently dropped. Consider decoding only the required fields (`ProcessId`, `ParentProcessId`) strictly and reading the optional fields defensively, as the previous implementation did.

const pid = record.ProcessId;
const ppid = record.ParentProcessId;
if (!Number.isInteger(pid) || pid <= 0 || !Number.isInteger(ppid) || ppid < 0) {
return Option.none();
}

const commandLine = nonEmptyStringOption(record.CommandLine).pipe(
Option.orElse(() => nonEmptyStringOption(record.Name)),
);
return Option.map(commandLine, (command) => ({
pid,
ppid,
pgid: null,
status: Option.getOrElse(nonEmptyStringOption(record.Status), () => "Live"),
cpuPercent:
typeof record.PercentProcessorTime === "number" &&
Number.isFinite(record.PercentProcessorTime)
? Math.max(0, record.PercentProcessorTime)
: 0,
rssBytes:
typeof record.WorkingSetSize === "number" && Number.isFinite(record.WorkingSetSize)
? Math.max(0, Math.round(record.WorkingSetSize))
: 0,
elapsed: "",
command,
}));
});
}

export function parseWindowsProcessRows(output: string): ReadonlyArray<ProcessRow> {
if (output.trim().length === 0) return [];
try {
const parsed = JSON.parse(output) as unknown;
const records = Array.isArray(parsed) ? parsed : [parsed];
return records.flatMap((record) => {
const row = normalizeWindowsProcessRow(record);
return row ? [row] : [];
});
} catch {
const parsed = decodeWindowsProcessJson(output);
if (Option.isNone(parsed)) {
return [];
}
const records = Array.isArray(parsed.value) ? parsed.value : [parsed.value];
return records.flatMap((record) =>
Option.match(normalizeWindowsProcessRow(record), {
onNone: () => [],
onSome: (row) => [row],
}),
);
}

export function buildDescendantEntries(
Expand Down Expand Up @@ -381,7 +397,7 @@ const runProcess = Effect.fn("runProcess")(function* (input: {
} satisfies ProcessOutput;
}).pipe(
Effect.scoped,
Effect.timeoutOption(Duration.millis(PROCESS_QUERY_TIMEOUT_MS)),
Effect.timeoutOption(PROCESS_QUERY_TIMEOUT),
Effect.flatMap((result) =>
Option.match(result, {
onNone: () =>
Expand All @@ -390,7 +406,7 @@ const runProcess = Effect.fn("runProcess")(function* (input: {
command: input.command,
argCount: input.args.length,
cwd,
timeoutMillis: PROCESS_QUERY_TIMEOUT_MS,
timeoutMillis: Duration.toMillis(PROCESS_QUERY_TIMEOUT),
}),
),
onSome: Effect.succeed,
Expand Down
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