RI-8267 Complete error-code coverage for i18n

[valkirilov]

What

Give every user-facing API error a stable errorCode (and structured resource data where it already exists) so the client can translate error messages on its own. The backend localizes nothing — it just exposes a code clients can map to a translated string.

Strictly additive & backwards-compatible:

• only new/optional response fields are added
• message (English), statusCode, and error/name are untouched.

Note: This API is also consumed by the Redis-for-VS-Code plugin, so not changing the response shape is a hard requirement.

Why

Pre-PR, ~58/78 custom exceptions carried an errorCode, but nothing was translatable for:

• ~27 codeless custom exceptions (SSH, encryption, database-import, RDI, misc),
• the ~149 built-in Nest exceptions (NotFoundException, BadRequestException, …),
• class-validator validation failures.

This PR closes those gaps so the upcoming UI work can map any error to a localized message, with the English message always available as a fallback. No nestjs-i18n / Accept-Language — translation stays client-side.

Commit breakdown (by change type)

1. Specific codes for codeless custom exceptions — add an errorCode from CustomErrorCodes to each, one line per file, response shape otherwise unchanged. Grouped per domain:

• feat(api): error codes for SSH exceptions
• feat(api): error codes for encryption exceptions
• feat(api): error codes for database-import exceptions
• feat(api): error codes for RDI exceptions (+ adds RdiTimeout, updates 2 specs)
• feat(api): error codes for misc exceptions (feature remote-config, redis client-not-found)

2. Generic chokepoint — feat(api): inject generic + validation error codes via global filter. GlobalExceptionFilter stamps a code onto any HttpException still missing one: ValidationError when message is an array (class-validator), otherwise a status-based Generic* code. Covers all built-in Nest throws + validation in one place, without editing ~149 throw sites. Custom-coded exceptions are left untouched.

3. Docs — docs(api): bruno error-code examples. A Bruno "Error Codes" folder with runnable requests showing each case.

New code-ranges in custom-error-codes.ts:

• SSH 116xx
• Database Import 117xx
• Encryption 118xx
• Misc 119xx
• Generic 124xx/125xx (12_000 + HTTP status)
• Validation 12100

Response shapes (with these changes)

Custom exception (now coded) — SSH:

{ 
    "message": "Unable to create ssh connection. ...", 
    "name": "UnableToCreateSshConnectionException", 
    "statusCode": 503, 
    "errorCode": 11600 
}

Generic built-in exception — 404 on an unknown id:

{ 
    "message": "Invalid database instance id.", 
    "statusCode": 404, 
    "error": "Not Found", 
    "errorCode": 12404
    }

Validation failure (note message stays an array of field errors):

{ 
     "message": ["port must be a number conforming to the specified constraints"], 
     "statusCode": 400, 
     "error": "Bad Request", 
     "errorCode": 12100 
 }

Exception carrying structured context — DatabaseAlreadyExists:

{ 
    "message": "The database already exists.", 
    "statusCode": 409, 
    "error": "DatabaseAlreadyExists", 
    "errorCode": 11200, 
    "resource": { 
        "databaseId": "a1b2c3d4-..." 
    } 
}

How we'll use this (next PR, UI — pseudo-code)

A small errorCode → i18n key map plus a translate helper. resource supplies interpolation vars.

Note: the English message is the fallback when a code isn't mapped yet.

// errorCodeMap.ts
const ERROR_CODE_TO_KEY: Record<number, string> = {
  11200: 'errors.database.alreadyExists',
  11600: 'errors.ssh.unableToConnect',
  12404: 'errors.notFound',
  12100: 'errors.validation',
}

// translateApiError.ts
export function translateApiError(err: ApiErrorResponse, t: TFunction): string {
  const key = err.errorCode ? ERROR_CODE_TO_KEY[err.errorCode] : undefined
  if (key) return t(key, err.resource)            // resource fills {{vars}} in the template
  return Array.isArray(err.message)               // fallback: keep the English message
    ? err.message.join(', ')
    : err.message
}

// locales/en.json                       // locales/bg.json
{ "errors.database.alreadyExists":       { "errors.database.alreadyExists":
    "The database already exists." }          "Базата данни вече съществува." }

// usage at an API error boundary / toast
catch (e) {
  showError(translateApiError(e.response.data, t))
}

So this PR is the data contract; the next PR adds the map + locale strings and wires translateApiError into the UI's error surfaces.

Testing

• yarn lint:api, yarn --cwd redisinsight/api type-check (baseline) — clean.
• yarn test:api — green; updated the 3 specs that asserted full getResponse() shapes, added a GlobalExceptionFilter spec (status→code mapping, validation array → ValidationError, doesn't overwrite existing codes, non-HttpException passthrough, static-asset branch).
• Manual: the Bruno Error Codes folder (POST /databases/test, GET /databases/:id) reproduces each case live against yarn dev:api.

---

Ref: RI-8267

Related community requests: #605, #1317, #1883, #2040, #2137, #2181, #2213, #2417, #2550, #2590, #2695, #2715, #2716, #2727, #2828, #2912, #2943, #2945, #3081, #3141, #3142, #3319, #3411, #3601, #3625, #3628, #3663, #3671, #3812, #3815, #4150, #4182, #4408, #4664, #4672, #4744, #5052, #5967

---

Note

Medium Risk
Broad change to global error serialization affects every API error path (including encryption/SSH), but behavior is additive and existing fields are preserved; regression risk is mainly wrong or missing codes on edge cases.

Overview
Adds an optional errorCode (and keeps existing resource where present) on API error responses so clients can translate errors without backend localization. message, statusCode, and error are unchanged.

Central stamping: New stampErrorCode runs in GlobalExceptionFilter for every HttpException missing a code—12100 when message is a class-validator array, otherwise 12_000 + HTTP status (e.g. 404 → 12404). Existing custom codes are not overwritten. The body-parser 413 path uses the same helper.

Domain exceptions: SSH, encryption, database-import, RDI (incl. RdiTimeout), remote-config, and redis client-not-found responses now set explicit CustomErrorCodes. ValidationException embeds ValidationError in its body.

Docs/tests: Bruno Error Codes requests document live shapes; new/updated specs cover the filter, body-parser, and RDI timeout/internal-error responses.

^{Reviewed by Cursor Bugbot for commit b04f7b1. Bugbot is set up for automated code reviews on this repo. Configure here.}

[jit-ci]

🛡️ Jit Security Scan Results

✅ No security findings were detected in this PR

---

^{Security scan by Jit}

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