typescript Errors

•Move the infer keyword inside a conditional type's extends clause: T extends infer U ? U : never
•Wrap your type in a conditional: type Result = T extends Array<infer U> ? U : T

typescript3 fixes

Path mapping not resolving module

Cannot find module '.*' or its corresponding type declarations

•Verify paths in tsconfig.json match the baseUrl-relative import pattern
•Ensure baseUrl is set correctly in tsconfig.json

typescript3 fixes

Declaration merging conflict

Duplicate identifier '.*'\. Compiler.*declaration merging

•Ensure merged declarations are in the same module scope (both global or both module-scoped)
•Check that interface properties don't conflict with incompatible types across declarations

typescript3 fixes

Mapped type indexing loses type narrowing

Property '.*' does not exist on type '.*\[keyof.*\]'

•Use a generic function with K extends keyof T to preserve the specific key type
•Add an explicit type assertion or use a conditional type to narrow the mapped result

typescript3 fixes

Template literal type combinatorial explosion

Template literal type.*produces a union type that is too complex

•Reduce the number of union members in the template literal constituents
•Split the type into smaller template literals and intersect or union them manually

typescript3 fixes

Project references missing composite flag

Referenced project '.*' must have setting.*composite.*true

•Add "composite": true to the referenced project's tsconfig.json compilerOptions
•Also add "declaration": true which is required when composite is enabled

typescript3 fixes

Decorator metadata reflection error

Unable to resolve signature of.*decorator when called as an expression

•Enable "emitDecoratorMetadata": true and "experimentalDecorators": true in tsconfig.json
•Ensure reflect-metadata is imported at the application entry point

typescript3 fixes

Module augmentation not found

Module '.*' has no exported member '.*'.*Did you mean to use 'import.*from'

•Ensure your augmentation file uses 'declare module' with the exact module specifier string
•The augmentation file must contain at least one top-level import or export to be treated as a module

typescript3 fixes

Infer constraint not satisfied in conditional type

Type '.*' does not satisfy the constraint '.*'.*infer

•Add an explicit constraint to the infer clause: infer U extends string
•Wrap the inferred type in a conditional check before using it

typescript3 fixes

Invalid mapped type syntax with extra properties

A mapped type may not declare properties or methods

•Use intersection type to combine mapped type with additional properties: MappedType & { extra: string }
•Move additional properties to a separate interface and intersect

typescript3 fixes

Namespace used as type instead of typeof

Cannot use namespace '.*' as a type

•Use typeof Namespace to get the type of the namespace object
•Import the specific type from the namespace: Namespace.TypeName

typescript3 fixes

Project reference output stale or missing

Output file '.*' has not been built from source file '.*'.*project reference

•Run tsc --build --force to rebuild all project references from scratch
•Delete the tsconfig.tsbuildinfo file and rebuild

typescript3 fixes

Deferred conditional type cannot be used directly

Type.*conditional type.*not yet resolved

•Add a type constraint to help TypeScript eagerly resolve the conditional
•Use a generic function instead of a type alias to defer evaluation to call site

typescript3 fixes

Mapped type needed instead of index signature

An index signature parameter type cannot be a literal type or generic type

•Use a mapped type [K in 'key1' | 'key2']: ValueType instead of index signature
•Use Record<'key1' | 'key2', ValueType> utility type

typescript3 fixes

Decorator applied to invalid target

Decorator.*not valid here.*only.*class declaration

•Ensure the decorator is applied to a class, method, accessor, property, or parameter (not a standalone function)
•Check that the decorator signature matches the target: ClassDecorator, MethodDecorator, PropertyDecorator, or ParameterDecorator

typescript3 fixes

This-type mismatch in mapped/conditional type

The 'this' context of type '.*' is not assignable to method's 'this' of type

•Use an arrow function to preserve the lexical 'this' context
•Add an explicit this parameter to the function signature: method(this: CorrectType, ...)

typescript3 fixes

Reflect API not available for decorator metadata

Cannot find name 'Reflect'.*emitDecoratorMetadata

•Install and import reflect-metadata: import 'reflect-metadata' at the top of your entry file
•Add "types": ["reflect-metadata"] to tsconfig.json compilerOptions

typescript3 fixes

Recursive mapped type exceeds depth limit

Excessive stack depth comparing types.*recursive

•Add a depth counter generic parameter and terminate recursion at a fixed depth
•Use interface extends instead of type aliases for recursive structures (interfaces are lazily evaluated)

typescript3 fixes

Prisma P2002 - unique constraint violation

P2002.*Unique constraint failed on the (fields|constraint).*$`(.*)`$

•Use upsert() instead of create() for records that might already exist
•Catch the P2002 error and return a user-friendly 'already exists' message

typescript3 fixes

Prisma P2003 - foreign key constraint violation

P2003.*Foreign key constraint failed on the field.*`(.*)`

•Ensure the referenced record exists before creating the child record
•Use connect syntax to link existing records: create({ data: { relation: { connect: { id } } } })

typescript3 fixes

Prisma P2025 - record not found for operation

P2025.*Record to (update|delete) not found|An operation failed because.*depends on.*record.*not found

•Use findUnique() first to check existence, then update/delete with a guard
•Use updateMany/deleteMany which return count 0 instead of throwing when no record matches

typescript3 fixes

Prisma migration drift detected

P3005.*database.*is not empty.*migration|drift detected.*schema

•Run prisma migrate diff to see what drifted from the expected schema
•Use prisma migrate resolve --applied <migration_name> to mark migrations as already applied

typescript3 fixes

Prisma schema validation error

P1012.*schema.*validation error|Error validating.*schema\.prisma

•Run prisma validate to get detailed error location in schema.prisma
•Check for missing relation annotations: every relation needs @relation on both sides

typescript3 fixes

Prisma connection pool timeout

P2024.*Timed out fetching a new connection from the connection pool

•Increase pool size in the connection string: ?connection_limit=20
•Reduce long-running transactions that hold connections from the pool

typescript3 fixes

Prisma P2021 - table not found in database

P2021.*table.*does not exist in the current database

•Run prisma migrate deploy to apply pending migrations that create the table
•Check DATABASE_URL points to the correct database

typescript3 fixes

Prisma P2022 - column not found in database

P2022.*column.*does not exist in the current database

•Run prisma migrate deploy to apply pending migrations that add the column
•Check if the column was renamed — update the @map() annotation or create a new migration

typescript3 fixes

Prisma cannot connect to database server

P1001.*Can't reach database server|Connection refused.*P1001

•Verify the database is running and accepting connections on the specified host:port
•Check DATABASE_URL format: postgresql://user:password@host:5432/dbname

typescript3 fixes

Prisma database operation timeout or closed connection

P1008.*Operations timed out|P1017.*Server has closed the connection

•Increase connection timeout in URL: ?connect_timeout=30
•Check for database server restarts or network instability

typescript3 fixes

Prisma P2014 - required relation violation

P2014.*change.*violates.*required relation.*between.*and

•Ensure the operation doesn't orphan required relations — delete children first or use cascade
•Set onDelete: Cascade in the @relation annotation if parent deletion should cascade

typescript3 fixes

Prisma query interpretation error

P2016.*Query interpretation error|Error interpreting the query

•Check for invalid filter combinations in your where clause
•Ensure relation filters use the correct nesting: where: { relation: { some: { field: value } } }

typescript3 fixes

Prisma client not generated or out of date

prisma generate.*ENOENT|Cannot find.*@prisma/client.*generate

•Run npx prisma generate to regenerate the client after schema changes
•Add prisma generate to your postinstall script: "postinstall": "prisma generate"

typescript3 fixes

Prisma migration failed - object already exists

P3006.*Migration.*failed to apply.*Error code.*already exists

•The migration is trying to create something that already exists — mark it as applied: prisma migrate resolve --applied <name>
•If the database was modified outside Prisma, baseline with prisma migrate diff

typescript3 fixes

Prisma unknown request error

PrismaClientUnknownRequestError|Unknown error.*Prisma Client

•Check database server logs for the actual error — Prisma couldn't categorize it
•Ensure the database version is compatible with your Prisma version

typescript3 fixes

Prisma related records not found during connect

P2015.*related record.*not found|P2018.*connected records.*not found

•Verify the ID or unique fields used in connect: { connect: { id: existingId } } point to real records
•Use connectOrCreate instead of connect if the related record might not exist yet

typescript3 fixes

Prisma interactive transactions not supported by provider

Prisma.*needs to perform transactions.*not supported.*provider

•Upgrade to Prisma 4.7+ for broader interactive transaction support
•Use sequential operations instead of interactive transactions for unsupported providers

typescript3 fixes

Prisma feature not supported by database provider

P2026.*current database provider doesn't support.*feature

•Check Prisma docs for provider-specific feature support (e.g., fullTextSearch requires PostgreSQL)
•Add the preview feature flag in schema.prisma: generator client { previewFeatures = ["feature"] }

typescript3 fixes

Prisma database seed script failure

Prisma.*seed.*error|prisma db seed.*failed

•Check the seed script path in package.json: "prisma": { "seed": "ts-node prisma/seed.ts" }
•For TypeScript seeds, ensure ts-node is installed and tsconfig allows the seed file

typescript3 fixes

Prisma query engine binary not found

PrismaClientInitializationError.*engine.*not found|Query engine.*binary.*not found

•Run prisma generate to download the correct engine binary for your platform
•Set binaryTargets in schema.prisma: generator client { binaryTargets = ["native", "linux-musl-openssl-3.0.x"] }

typescript4 fixes