[BUG]: `createInsertSchema` from `drizzle-zod@0.6.1` does not infer types correctly but returns `unknown` for every value
Problem
Report hasn't been filed before. - [X] I have verified that the bug I'm about to report hasn't been filed before. What version of `drizzle-orm` are you using? 0.38.3 What version of `drizzle-kit` are you using? 0.30.1 Other packages drizzle-zod@0.6.1,zod@3.24.1,typescript@5.7.2 Describe the Bug What is the undesired behavior? When using `createInsertSchema` provided by `drizzle-zod` to build a type-safe schema based on a table definition, it seems that the types are not properly inferred when the resulting schema is used to parse data. The keys in the resulting schema overlap with the table but all values are `unknown` (and optional). _Screenshot_ <img width="791" alt="example" src="https://github.com/user-attachments/assets/80a4a8de-5098-44a7-85a4-624bd95a099a" /> What are the steps to reproduce it? 1. Install packages with the following `package.json`: [code block] 2. Copy the example code from the docs. Slightly edited version below: [code block] 3. Launch editor and inspect types 🤓 What is the desired result? Ideally I'd like the types to be inferred properly "before" and "after" the use of `createInsertSchema` (and similar helpers) from `drizzle-zod` so that I can use the resulting schema (including specificed overwrites) for type-safe parsing of data.
Error Output
Error: no test specified\" && exit 1"
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1 Fix
Fix Type Inference Issue in createInsertSchema of drizzle-zod
The issue arises from the way types are inferred in the createInsertSchema function of drizzle-zod. The function does not correctly map the types from the table definition to the resulting schema, leading to all values being inferred as 'unknown'. This is likely due to a mismatch in the expected types and how they are processed within the function.
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- 1
Update Type Definitions
Modify the type definitions in the drizzle-zod package to ensure that the types are correctly inferred from the table schema. This may involve adjusting the generics used in the createInsertSchema function.
typescripttype CreateInsertSchema<T> = { [K in keyof T]: T[K] | undefined }; - 2
Add Type Assertions
In the createInsertSchema function, add type assertions to ensure that the inferred types are correctly interpreted. This can help in resolving the 'unknown' type issue.
typescriptconst schema = z.object({ ...tableDefinition }) as CreateInsertSchema<typeof tableDefinition>; - 3
Test with Sample Data
Create a test case that uses the createInsertSchema function with a sample table definition and validate that the types are inferred correctly. This will help confirm that the changes made are effective.
typescriptconst schema = createInsertSchema(sampleTableDefinition); const result = schema.parse({ column1: 'value', column2: 123 }); // Should not throw an error - 4
Update Documentation
Ensure that the documentation for drizzle-zod is updated to reflect the changes made to the type inference process. This will help users understand how to use the createInsertSchema function effectively.
markdown// Update README.md with examples of correct usage - 5
Publish Updated Package
Once the changes have been validated, publish the updated drizzle-zod package to npm to ensure that users can access the fix.
bashnpm publish
Validation
To confirm the fix worked, run the updated createInsertSchema function with a sample table definition and check that the inferred types are correct. Additionally, ensure that no values are inferred as 'unknown' and that the schema correctly validates the input data.
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Environment
Submitted by
Alex Chen
2450 rep