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fix(shell): drain stdout/stderr to prevent command hanging on large output #154

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Merged
skulidropek merged 3 commits into from
Mar 18, 2026
Merged

fix(shell): drain stdout/stderr to prevent command hanging on large output #154

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129ad1d
Initial commit with task details
konard Mar 18, 2026
aa4920a
fix(shell): drain stdout/stderr in runCommandExitCode and runCommandC…
konard Mar 18, 2026
4ce98ef
Revert "Initial commit with task details"
konard Mar 18, 2026
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30 changes: 18 additions & 12 deletions packages/lib/src/shell/command-runner.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -47,24 +47,28 @@ export const runCommandWithExitCodes = <E>(
yield* _(ensureExitCode(numericExitCode, okExitCodes, onFailure))
})

// CHANGE: run a command and return the exit code
// WHY: enable status checks without throwing on non-zero exits
// CHANGE: run a command and return the exit code, draining stdout/stderr to prevent buffer deadlock
// WHY: piped stdout/stderr fill the OS buffer (~64 KB) causing the child process to hang indefinitely
// QUOTE(ТЗ): "система авторизации"
// REF: user-request-2026-01-28-auth
// SOURCE: n/a
// FORMAT THEOREM: forall cmd: exitCode(cmd) = n
// PURITY: SHELL
// EFFECT: Effect<number, PlatformError, CommandExecutor>
// INVARIANT: stdout/stderr are suppressed for status checks
// INVARIANT: stdout/stderr are drained asynchronously so the child process never blocks
// COMPLEXITY: O(command)
export const runCommandExitCode = (
spec: RunCommandSpec
): Effect.Effect<number, PlatformError, CommandExecutor.CommandExecutor> =>
Effect.map(
Command.exitCode(
buildCommand(spec, "pipe", "pipe", "pipe")
),
Number
Effect.scoped(
Effect.gen(function*(_) {
const executor = yield* _(CommandExecutor.CommandExecutor)
const process = yield* _(executor.start(buildCommand(spec, "pipe", "pipe", "pipe")))
yield* _(Effect.forkDaemon(Stream.runDrain(process.stdout)))
yield* _(Effect.forkDaemon(Stream.runDrain(process.stderr)))
const exitCode = yield* _(process.exitCode)
return Number(exitCode)
})
)

const collectUint8Array = (chunks: Chunk.Chunk<Uint8Array>): Uint8Array =>
Expand All @@ -75,15 +79,15 @@ const collectUint8Array = (chunks: Chunk.Chunk<Uint8Array>): Uint8Array =>
return next
})

// CHANGE: run a command and capture stdout
// WHY: allow auth flows to retrieve tokens from CLI tools
// CHANGE: run a command and capture stdout, draining stderr to prevent buffer deadlock
// WHY: if stderr fills the OS buffer (~64 KB) the child process hangs; drain it asynchronously
// QUOTE(ТЗ): "система авторизации"
// REF: user-request-2026-01-28-auth
// SOURCE: n/a
// FORMAT THEOREM: forall cmd: capture(cmd) -> stdout(cmd)
// PURITY: SHELL
// EFFECT: Effect<string, E | PlatformError, CommandExecutor>
// INVARIANT: stderr is captured but ignored for output
// INVARIANT: stderr is drained asynchronously; stdout is fully collected before returning
// COMPLEXITY: O(command)
export const runCommandCapture = <E>(
spec: RunCommandSpec,
Expand All @@ -94,11 +98,13 @@ export const runCommandCapture = <E>(
Effect.gen(function*(_) {
const executor = yield* _(CommandExecutor.CommandExecutor)
const process = yield* _(executor.start(buildCommand(spec, "pipe", "pipe", "pipe")))
yield* _(Effect.forkDaemon(Stream.runDrain(process.stderr)))
const bytes = yield* _(
pipe(process.stdout, Stream.runCollect, Effect.map((chunks) => collectUint8Array(chunks)))
)
const exitCode = yield* _(process.exitCode)
yield* _(ensureExitCode(Number(exitCode), okExitCodes, onFailure))
const numericExitCode = Number(exitCode)
yield* _(ensureExitCode(numericExitCode, okExitCodes, onFailure))
return new TextDecoder("utf-8").decode(bytes)
})
)
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