Analyzer Showcase

Each example comes from a TypeScript fixture in the analyzer test suite. Switch between the diagram and its source. Runtime examples add a recorded-run tab over the same static graph. Open steps analyzed to inspect inferred output types, error unions, dependency policies, and step metadata.

Start with the examples that match the work in front of you:

You need to inspect	Open this example
A short request handler	Linear steps
Retry and timeout policy declared on dependencies	run() with dependency policies
Branches, parallel work, and iteration in one graph	Complex (parallel + conditional + forEach)
Ownership, external calls, state changes, and error severity	Architecture and error metadata
Rollback order after a partial failure	Saga workflow
Where cancellation stopped work	Cancellation: recorded run
Which steps resumed from saved state	Persistence: resumed run
Rollback order and a failed undo	Saga rollback and compensation failure

The analyzer generates the diagrams below from the source shown beside them. Recorded runs pass through the same trace overlay used by the CLI and live inspector. Edit a step id, branch, policy, or error type in the fixture and regenerate the data; the diagram and step facts change with the code.

Linear steps

Result:Promise<{ user: User; orders: Order[]; }>Errors:NOT_FOUNDFETCH_ERRORSEND_ERROR

DiagramSource

3 steps analyzed

getUserdeps.fetchUser

dep: fetchUserNOT_FOUND→ Usererr: "NOT_FOUND"

getOrdersdeps.fetchOrders

dep: fetchOrdersFETCH_ERROR→ Order[]err: "FETCH_ERROR"

notifydeps.sendEmail

dep: sendEmailSEND_ERRORerr: "SEND_ERROR"

step.sleep

Result:Promise<string>

DiagramSource

2 steps analyzed

pausestep.sleep

sleep

longPausestep.sleep

sleep

step.retry

Result:Promise<{ data: string; }>Errors:NETWORK_ERROR

DiagramSource

1 step analyzed

fetchstep.retry

dep: fetchDataretryNETWORK_ERRORretry: 3 exponential→ { data: string; }err: "NETWORK_ERROR"

step.withTimeout

Result:Promise<number>Errors:TIMEOUT

DiagramSource

1 step analyzed

slowCallstep.withTimeout

dep: slowOpwithTimeoutTIMEOUTtimeout: 5000ms→ numbererr: "TIMEOUT"

step.try & step.fromResult

Result:Promise<string>Errors:RISKY_ERRORFETCH_ERROR

DiagramSource

2 steps analyzed

attemptstep.try

dep: riskyOptryRISKY_ERROR→ numbererr: "RISKY_ERROR"

loadstep.fromResult

dep: fetchResultfromResultFETCH_ERROR→ stringerr: "FETCH_ERROR"

step.withFallback

Result:Promise<string>Errors:NOT_FOUNDnever

DiagramSource

1 step analyzed

fetchWithFallbackstep.withFallback

dep: fetchPrimaryNOT_FOUND→ stringerr: "NOT_FOUND"

step.withResource

Result:Promise<string>Errors:ACQUIRE_ERRORUSE_ERROR

DiagramSource

1 step analyzed

useConnstep.withResource

withResourcedeps.acquire → deps.useResource → inline

step.dep

Result:Promise<{ id: string; }>Errors:NOT_FOUND

DiagramSource

1 step analyzed

getUserdeps.fetchUser

dep: userServiceNOT_FOUND→ { id: string; }err: "NOT_FOUND"

step.race

Result:Promise<string>Errors:MISS

DiagramSource

2 steps analyzed

race.0.cacheAdeps.cacheA

dep: cacheAMISS→ stringerr: "MISS"

race.1.cacheBdeps.cacheB

dep: cacheBMISS→ stringerr: "MISS"

when / unless / whenOr / unlessOr

Result:Promise<ConditionalResult>Errors:AUDIT_FAILEDCOMPUTE_ERROR

DiagramSource

4 steps analyzed

whenStepdeps.audit

dep: auditAUDIT_FAILED→ booleanerr: "AUDIT_FAILED"

unlessStepdeps.compute

dep: computeCOMPUTE_ERROR→ numbererr: "COMPUTE_ERROR"

whenOrStepdeps.audit

dep: auditAUDIT_FAILED→ booleanerr: "AUDIT_FAILED"

unlessOrStepdeps.compute

dep: computeCOMPUTE_ERROR→ numbererr: "COMPUTE_ERROR"

switch

Result:Promise<string>Errors:ADMIN_ERRORUSER_ERRORnever

DiagramSource

3 steps analyzed

admindeps.adminAction

dep: adminActionADMIN_ERRORerr: "ADMIN_ERROR"

userdeps.userAction

dep: userActionUSER_ERRORerr: "USER_ERROR"

defaultdeps.defaultAction

dep: defaultAction

for / while / for-of / for-in

Result:Promise<string>Errors:PROCESS_ERROR

DiagramSource

4 steps analyzed

forStepdeps.processItem

dep: processItemPROCESS_ERRORloop: forerr: "PROCESS_ERROR"

forOfStepdeps.processItem

dep: processItemPROCESS_ERRORloop: itemserr: "PROCESS_ERROR"

forInStepdeps.processItem

dep: processItemPROCESS_ERRORloop: objerr: "PROCESS_ERROR"

whileStepdeps.processItem

dep: processItemPROCESS_ERRORloop: n < 2err: "PROCESS_ERROR"

Workflow ref

Result:Promise<{ user: User; enriched: Enriched; }>Errors:NOT_FOUND

DiagramSource

2 steps analyzed

getUserdeps.fetchUser

dep: fetchUserNOT_FOUND→ Usererr: "NOT_FOUND"

callChilddeps.enrichUser

dep: enrichUserENRICH_ERRORUnexpectedError→ Enrichederr: "ENRICH_ERROR" | UnexpectedError

Complex (parallel + conditional + forEach)

Result:Promise<ComplexResult>Errors:ERR

DiagramSource

4 steps analyzed

parallel.fetchBoth.fetchAdeps.fetchA

dep: fetchAERR→ stringerr: "ERR"

parallel.fetchBoth.fetchBdeps.fetchB

dep: fetchBERR→ stringerr: "ERR"

forEach.processAll.processItemdeps.processItem

dep: processItemERRloop: items→ stringerr: "ERR"

fetchAOnlydeps.fetchA

dep: fetchAERR→ stringerr: "ERR"

Saga workflow

Result:Promise<{ reservation: { reservationId: string; }; payment: { chargeId: string; }; }>Errors:UNAVAILABLERELEASE_FAILEDCHARGE_FAILEDNOTIFY_FAILED

DiagramSource

3 steps analyzed

Reservedeps.reserve

dep: reservecompensableundo: release

Chargedeps.charge

dep: chargecompensable

Notifydeps.notify

dep: notifytry

run() with dependency policies

Result:Promise<{ user: User; orders: Order[]; }>Errors:USER_NOT_FOUNDORDERS_UNAVAILABLETimeoutError

DiagramSource

2 steps analyzed

getUsergetUser

dep: getUserUSER_NOT_FOUND→ Usererr: "USER_NOT_FOUND"

getOrdersgetOrders

dep: getOrderstimeout policyretry policyORDERS_UNAVAILABLE→ Order[]err: "ORDERS_UNAVAILABLE"

Policies:

timeout(2_000) → retry({ attempts: 3, delay: 100, backoff: "exponential", })

Architecture and error metadata

Result:Promise<Payment>Errors:PaymentError

DiagramSource

1 step analyzed

charge-carddeps.chargeCard

dep: chargeCardCARD_DECLINEDGATEWAY_TIMEOUT→ Paymenterr: PaymentErrorpaymentscheckout-teamside-effectexternal-apipci

Intent:

Collect payment before fulfillment starts

Calls:

payment-gateway

State:

order.paymentStatus -> PAID

Emits:

PaymentCaptured

Errors:

CARD_DECLINED · business · no retry; GATEWAY_TIMEOUT · infrastructure · retryable

Cancellation: recorded run

Result:Promise<Profile>Errors:PROFILE_FAILEDEMAIL_FAILED

Static graphCancelled runSource

2 steps analyzed

loadProfiledeps.loadProfile

dep: loadProfilePROFILE_FAILED→ Profileerr: "PROFILE_FAILED"

sendEmaildeps.sendEmail

dep: sendEmailEMAIL_FAILED→ "sent"err: "EMAIL_FAILED"

Persistence: resumed run

Result:Promise<{ reservation: { id: string; }; payment: { id: string; }; }>Errors:OUT_OF_STOCKPAYMENT_FAILED

Static graphResumed runSource

2 steps analyzed

reserveStockdeps.reserveStock

dep: reserveStockOUT_OF_STOCK→ { id: string; }err: "OUT_OF_STOCK"

chargedeps.charge

dep: chargePAYMENT_FAILED→ { id: string; }err: "PAYMENT_FAILED"

Saga rollback and compensation failure

Result:Promise<{ payment: { id: string; }; stock: { id: string; }; }>Errors:DECLINEDREFUND_FAILEDOUT_OF_STOCKRELEASE_FAILEDSHIPMENT_FAILED

DiagramSource

3 steps analyzed

chargedeps.charge

dep: chargecompensableundo: refund

reservedeps.reserve

dep: reservecompensableundo: release

shipdeps.ship

dep: ship

Use Static Analysis for CI, diffs, test matrices, and trace overlays. Visualization covers runtime event streams.