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tessl/npm-backstage--errors

Common utilities for error handling within Backstage with structured error classes and serialization functions

63

1.28x
Overview
Eval results
Files

Evaluation results

0%

-15%

Pipeline Error Handling

Custom error base with cause-aware messages

Criteria
Without context
With context

Base inheritance

0%

0%

Cause retention

50%

0%

Message chaining

0%

0%

Subclass naming

0%

0%

Guard helpers

25%

0%

55%

-35%

Error Shape Utilities

Error shape guards (isError/assertError)

Criteria
Without context
With context

Use isError

100%

60%

Assert invalid

66%

16%

Shape to Error

100%

75%

Skip non-errors

100%

80%

60%

45%

Error Log Transcoder

Error serialization helpers (serialize/deserialize/stringify)

Criteria
Without context
With context

Default serialization

0%

60%

Stack opt-in

0%

100%

Cause capture

0%

32%

Error rehydration

0%

40%

Unknown stringify

100%

100%

49%

25%

Wrapped Error Toolkit

Cause filtering and enrichment for wrapped errors

Criteria
Without context
With context

Base wrapper

32%

20%

Cause filtering

53%

53%

Forwarded context

40%

50%

Serialization default

0%

60%

Stack opt-in

0%

80%

Roundtrip rebuild

0%

60%

22%

-3%

Tolerant Error Response Parser

Tolerant parsing of error response bodies

Criteria
Without context
With context

Delegate parsing

0%

0%

Content-type aware

0%

25%

Fallback retention

100%

46%

Error fidelity

0%

33%

Response metadata

66%

33%

100%

Structured Fetch Error Handler

ResponseError builder for failed fetch responses

Criteria
Without context
With context

ResponseError usage

100%

100%

Status metadata

100%

100%

Error body & cause

100%

100%

Fallback parsing

100%

100%

98%

98%

Error Serialization Toggle

Opt-in stack inclusion during error serialization

Criteria
Without context
With context

Default omit

0%

100%

Stack opt-in

0%

100%

Cause handling

0%

100%

Serialized shape

0%

90%

100%

HTTP Error Translator

Standard Backstage HTTP-style error classes

Criteria
Without context
With context

Bad request class

100%

100%

Auth class

100%

100%

Forbidden class

100%

100%

Missing resource class

100%

100%

Conflict class

100%

100%

Cause chaining

100%

100%

100%

Upstream Error Forwarding

ForwardedError propagating upstream names

Criteria
Without context
With context

Uses ForwardedError

100%

100%

Cause attached

100%

100%

Context message

100%

100%

Fallback name

100%

100%

48%

30%

Structured Remote Error Payloads

Typed error payload shapes (ErrorResponseBody, ConsumedResponse)

Criteria
Without context
With context

Typed response input

0%

25%

Payload typing

0%

32%

Parse helper reuse

0%

0%

Fallback serialization

66%

100%

Error rebuild

40%

100%

Install with Tessl CLI

npx tessl i tessl/npm-backstage--errors
Evaluated
Agent
Claude Code

Table of Contents

Pipeline Error HandlingError Shape UtilitiesError Log TranscoderWrapped Error ToolkitTolerant Error Response ParserStructured Fetch Error HandlerError Serialization ToggleHTTP Error TranslatorUpstream Error ForwardingStructured Remote Error Payloads