fix(postgrest): preserve nullability when using JSON path #1939

dev-hari-prasad · 2025-12-10T17:27:56Z

Description:
What changed?
Fixed the type inference for JSON path selections (->) by adding | null when the underlying JSON column can be null.

Why was this change needed?
When selecting a JSON path from a nullable JSON column, the generated TypeScript types incorrectly assumed the value could never be null.
In reality, the runtime returns null when the whole column is null, so the types were unsafe.
This patch brings the inferred type in line with actual behavior.

Closes/Fixes #1635

Screenshots/Examples:
N/A since it is a type-only change.

Breaking changes:
This PR contains no breaking changes.

📋 Checklist:

I have read the Contributing Guidelines
My PR title follows the conventional commit format: <type>(<scope>): <description>
I have run npx nx format to ensure consistent code formatting
I have added tests for new functionality (if applicable)
I have updated documentation (if applicable)

Additional notes:
The change is intentionally minimal and only affects the nullable branch of JsonPathToType.
It preserves existing behavior for non-nullable JSON columns while correctly reflecting actual return values for nullable ones.

CC @avallete & @mandarini

…upabase#1635) The JSON path resolver (JsonPathToType) stripped `null` using Exclude<T, null> but never added it back to the resulting type. This caused `.select('col->a')` to infer a non-nullable type even when the underlying JSON column was nullable. Example: json_col: { a: string } | null .select('json_col->a') // inferred `string` instead of `string | null` This patch re-attaches `| null` when the root JSON column contains null, ensuring correct type inference for nullable JSON columns and nullable nested paths. Fixes: supabase#1635

mandarini · 2025-12-15T19:34:56Z

Thanks for the fix @dev-hari-prasad ! This correctly addresses the nullability issue in #1635. However, since this changes type inference in a way that could cause compilation errors for existing users (nullable JSON paths will now correctly return T | null instead of T), I will be treating this as a breaking change.

Before merging, could you please:

Add type tests that verify the new nullable behavior
Update any existing type tests that may be affected

I'll tag this for v3 (next major release). And we can merge it when the time comes!

coveralls · 2025-12-15T19:43:12Z

coverage: 95.349% (+14.1%) from 81.261%
when pulling 9a0e074 on dev-hari-prasad:fix/Null-should-be-included-in-return-type
into 31280b2 on supabase:master.

dev-hari-prasad · 2025-12-16T00:17:47Z

Before merging, could you please:

Add type tests that verify the new nullable behavior

Update any existing type tests that may be affected

Sure

Added tests to verify JsonPathToType correctly returns T | null when accessing paths on nullable JSON columns. Also updated existing tests to reflect the new nullable behavior in type expectations.

dev-hari-prasad · 2025-12-16T11:08:18Z

@mandarini Tests are now added, let me know if anything else is required

mandarini · 2025-12-16T12:44:05Z

Thanks @dev-hari-prasad ! We'll wait for v3 now!

avallete

A few comments, I think we should add more tests over the runtime behavior of this to ensure we don't regress on it further down the line.

packages/core/postgrest-js/test/index.test-d.ts

packages/core/postgrest-js/test/relationships.test.ts

packages/core/postgrest-js/test/types.override.ts

dev-hari-prasad · 2025-12-18T11:43:46Z

Happy to update or rewrite the affected tests as part of this pr. Just let me know if you’d like me to take that on, or if you prefer to handle it internally.

@mandarini @avallete

avallete · 2025-12-19T09:42:05Z

Happy to update or rewrite the affected tests as part of this pr. Just let me know if you’d like me to take that on, or if you prefer to handle it internally.

@mandarini @avallete

Hey @dev-hari-prasad first of all, thanks a lot for the contribution!

You’re very welcome to address the comments I left, that would be much appreciated and should help speed up getting this merged and released.

Otherwise, I can look into adding or updating the tests myself once I have the bandwidth.

…l-should-be-included-in-return-type

avallete · 2026-01-07T20:06:38Z

I don't expect this to really be a BC anymore. But as @mandarini mentioned, some users might rely over the "non null" behavior so that might break their typecheck (even if that's more correct).

mandarini · 2026-01-08T12:44:24Z

hmmm i don't know what happened, i did not close this. give me a moment

mandarini · 2026-01-08T12:46:22Z

i merged the other PR so base branch got deleted. give me a moment to fix this

mandarini · 2026-01-08T13:11:45Z

Yeah, something weird happen, and we cannot reopen the PR and target the master branch, this is what github copilot says:

What happened to this PR

This PR was automatically closed when its base branch (chore/add-supabase-cli-as-devdeps-package) was merged to master and subsequently deleted.

Timeline of events:

PR created: fix/Null-should-be-included-in-return-type → chore/add-supabase-cli-as-devdeps-package
Base branch merged: chore/add-supabase-cli-as-devdeps-package was merged into master and deleted
PR auto-closed: GitHub closed this PR instead of retargeting it to master

Why GitHub closed it instead of retargeting:

The head branch (fix/Null-should-be-included-in-return-type) was based on chore/add-supabase-cli-as-devdeps-package and contained all of its commits plus additional changes. When the base branch was merged to master, those commits became part of master, creating an ambiguous situation where many commits in this PR were now already in the target branch.

Rather than auto-retarget and show duplicate commits, GitHub closed the PR.

Next steps:

I created a new PR (#2011) that:

Targets master directly
Contains only the unique commits from this branch (rebased onto master)
Preserves the fix for preserving nullability when using JSON path

Thanks @dev-hari-prasad for the contribution! The work continues in the new PR.

dev-hari-prasad requested review from a team as code owners December 10, 2025 17:27

mandarini changed the title ~~fix(postgrest-js): preserve nullability when using JSON path (->) (#1635)~~ fix(postgrest): preserve nullability when using JSON path (->) (#1635) Dec 15, 2025

mandarini force-pushed the fix/Null-should-be-included-in-return-type branch from 60a5dcc to 621e051 Compare December 15, 2025 15:37

mandarini added the postgrest-js Related to the postgrest-js library. label Dec 15, 2025

mandarini added v3 Planned for v3 do-not-merge Do not merge this PR. labels Dec 15, 2025

mandarini self-assigned this Dec 15, 2025

mandarini changed the title ~~fix(postgrest): preserve nullability when using JSON path (->) (#1635)~~ fix(postgrest): preserve nullability when using JSON path (#1635) Dec 15, 2025

mandarini changed the title ~~fix(postgrest): preserve nullability when using JSON path (#1635)~~ fix(postgrest): preserve nullability when using JSON path Dec 15, 2025

test(postgrest): add type tests for nullable JSON path behavior

d33fe58

Added tests to verify JsonPathToType correctly returns T | null when accessing paths on nullable JSON columns. Also updated existing tests to reflect the new nullable behavior in type expectations.

avallete reviewed Dec 16, 2025

View reviewed changes

avallete added 8 commits December 23, 2025 17:36

test(postgrest): add some tests around json accessors type inference

200ad1c

fix(postgrest): keep union and add null to inference

bb242aa

chore(postgrest): make custom json data override schema nullable

3a7f9b4

test(postgrest): add json path tests for non-nullable json

a3e0725

test(postgrest): fix returns.test-d.ts expect

ba0fcf4

test(postgrest): fix index.test-d.ts tests

9a0e074

Merge branch 'master' into fix/Null-should-be-included-in-return-type

b77e8a4

Merge branch 'chore/add-supabase-cli-as-devdeps-package' into fix/Nul…

aa2c0e7

…l-should-be-included-in-return-type

avallete requested review from a team as code owners January 7, 2026 19:45

avallete changed the base branch from master to chore/add-supabase-cli-as-devdeps-package January 7, 2026 19:45

avallete approved these changes Jan 7, 2026 •

edited

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mandarini deleted the branch supabase:chore/add-supabase-cli-as-devdeps-package January 8, 2026 12:39

mandarini closed this Jan 8, 2026

mandarini mentioned this pull request Jan 8, 2026

fix(postgrest): preserve nullability when using JSON path #2011

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fix(postgrest): preserve nullability when using JSON path #1939

fix(postgrest): preserve nullability when using JSON path #1939

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