[data grid] Fix crash in `getRowValue` when `colDef` is undefined by LukasTy · Pull Request #22838 · mui/mui-x

LukasTy · 2026-06-16T15:26:26Z

What

getRowValue (gridRowsUtils.ts) read colDef.field before its own if (!colDef) guard, so the guard was dead code. Any caller passing an undefined colDef crashed with:

TypeError: Cannot read properties of undefined (reading 'field')

This reorders the guard so the dereference is safe, hardens the row-spanning getCellValue the same way, documents the premium aggregation value-getter closure (now safe via the guarded getRowValue), and applies the same guard to the Premium getRowValue/getRowFormattedValue overrides.

Why / how it is reachable

A colDef looked up by field is undefined when the field is not in the current column lookup -- e.g. getColumn(field) returning undefined, which flows into getRowValue via getCellParams -> getCellParamsForRow. The minimal reproduction:

apiRef.current.getCellParams(1, 'does-not-exist')

The fix lives in getRowValue so it holds regardless of which caller trips it.

DataGridPro routes through the community getRowValue, so it is covered by the community fix. DataGridPremium overrides getRowValue/getRowFormattedValue (for aggregation results) and dereferenced colDef.field before delegating, so it still crashed on the same input -- this PR guards those overrides too.

Note on the premium aggregation closure: adding if (!column) continue there would have been wrong, as it would move the crash to the valueGetters[field]! call site. With the guard in place, getRowValue(row, undefined) returns undefined, which is already filtered out when aggregating.

Testing

Added regression tests calling getCellParams(id, unknownField) for DataGrid (cells.DataGrid.test.tsx), DataGridPro (rows.DataGridPro.test.tsx), and DataGridPremium (aggregation.DataGridPremium.test.tsx). Verified red -> green for each: they throw the reported TypeError before the fix and pass after.

Verified: x-data-grid jsdom suite, rowSpanning browser tests, full x-data-grid-premium unit suite, TypeScript (community + pro + premium), ESLint, and Prettier all pass.

I have followed (at least) the PR section of the contributing guide.

`getRowValue` read `colDef.field` before its own `if (!colDef)` guard, so the guard was dead code and any caller passing an undefined `colDef` threw `TypeError: Cannot read properties of undefined (reading 'field')`. This is reachable whenever a `colDef` is looked up by field and the field is not in the current column lookup (e.g. `getColumn(field)` returning `undefined` via `getCellParams`). Reorder the guard so the dereference is safe, and harden the row-spanning `getCellValue` the same way. The premium aggregation value-getter closure also passes a possibly `undefined` column to `getRowValue`; with the guard in place it now returns `undefined` (filtered out when aggregating) instead of crashing. Closes mui#22831 Co-Authored-By: Claude Opus 4.8 <[email protected]>

code-infra-dashboard · 2026-06-16T15:31:01Z

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Bundle size

Bundle	Parsed size	Gzip size
@mui/x-data-grid	🔺+5B^(0.00%)	0B^(0.00%)
@mui/x-data-grid-pro	🔺+5B^(0.00%)	🔺+1B^(0.00%)
@mui/x-data-grid-premium	🔺+19B^(0.00%)	🔺+6B^(0.00%)
@mui/x-charts	0B^(0.00%)	0B^(0.00%)
@mui/x-charts-pro	0B^(0.00%)	0B^(0.00%)
@mui/x-charts-premium	0B^(0.00%)	0B^(0.00%)
@mui/x-date-pickers	0B^(0.00%)	0B^(0.00%)
@mui/x-date-pickers-pro	0B^(0.00%)	0B^(0.00%)
@mui/x-tree-view	0B^(0.00%)	0B^(0.00%)
@mui/x-tree-view-pro	0B^(0.00%)	0B^(0.00%)
@mui/x-license	0B^(0.00%)	0B^(0.00%)

Details of bundle changes

Check out the code infra dashboard for more information about this PR.

…alue` The Premium overridable param methods dereferenced `colDef.field` before delegating to the (now guarded) community `getRowValue`, so `DataGridPremium.getCellParams(id, unknownField)` still crashed with `TypeError: Cannot read properties of undefined (reading 'field')`. Guard `colDef` in both overrides so the Premium path is as tolerant as the community one. `DataGridPro` was already covered since it does not override these methods. Add regression tests for both Pro and Premium. Co-Authored-By: Claude Opus 4.8 <[email protected]>

Copilot

Pull request overview

This PR fixes a runtime crash in the Data Grid params/value resolution path when a column definition lookup returns undefined (e.g. apiRef.current.getCellParams(id, 'unknown-field')), by ensuring colDef is guarded before dereferencing colDef.field. It also adds regression tests across Community/Pro/Premium, and hardens related row-spanning and Premium aggregation paths that indirectly rely on getRowValue.

Changes:

Reorders/strengthens colDef guarding in getRowValue (community) and related row-spanning getCellValue.
Adds regression tests ensuring getCellParams(id, unknownField) does not throw in Community, Pro, and Premium.
Guards Premium getRowValue/getRowFormattedValue overrides and documents why aggregation value-getters may receive an undefined column.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/x-data-grid/src/hooks/features/rows/gridRowsUtils.ts	Moves the `!colDef` guard before field dereference in `getRowValue` to prevent crashes.
packages/x-data-grid/src/hooks/features/rows/gridRowSpanningUtils.ts	Adds a `colDef` guard to row-spanning `getCellValue` to avoid null dereferences.
packages/x-data-grid-premium/src/hooks/features/rows/useGridParamsOverridableMethods.ts	Adds `colDef` guards to Premium params overrides to avoid dereferencing `colDef.field` when missing.
packages/x-data-grid-premium/src/hooks/features/aggregation/createAggregationLookup.ts	Documents that aggregation can see `undefined` columns and relies on guarded `getRowValue`.
packages/x-data-grid/src/tests/cells.DataGrid.test.tsx	Adds a regression test for `getCellParams(id, unknownField)` in Community.
packages/x-data-grid-pro/src/tests/rows.DataGridPro.test.tsx	Adds a regression test for `getCellParams(id, unknownField)` in Pro.
packages/x-data-grid-premium/src/tests/aggregation.DataGridPremium.test.tsx	Adds a regression test for `getCellParams(id, unknownField)` in Premium.

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Address review feedback: type the internal `getRowValue`/`getCellValue` `colDef` params as `GridColDef | undefined` so the guards are no longer dead code against the type, and return `undefined` directly in the Premium `getRowValue` override instead of delegating with an `undefined` colDef. Co-Authored-By: Claude Opus 4.8 <[email protected]>

Copilot

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated no new comments.

MBilalShafi · 2026-06-19T15:38:50Z

+      if (!colDef) {
+        return undefined;
+      }


Kind of a Nitpick:

Just like this guard, would it be better to also add a guard on the community API method, that makes sure that the method is not invoked at all if the necessary params (in this case colDef) are not available?

Also, the interface GridParamsApi['getRowValue'] doesn't correctly point out the expected input type for colDef param that supports undefined too now. But changing it may touch the public API interface (possibly be considered a BC too).

So probably either of:

Add guards on both the API entry points (premium and community), remove the redundant one from the util, and make sure all the entry points to this util go through the API.

Add a guard only on the util with the updated TS interface that reflects that, and the API methods pass the param without any gate-keeping.

Having guards at both levels feels a little bit redundant.

Wdyt?

Good point, went with your option 2.

Option 1 isn't quite feasible: the util getRowValue has callers that intentionally bypass the API, most notably row spanning's getCellValue, which calls it directly during state initialization (before apiRef.current.getRowValue is ready -- there's a comment to that effect), plus row grouping and the Premium filter value-getter config. So the util has to stay the defensive layer.

So the single guard now lives in the util (typed colDef: GridColDef | undefined), and the Premium overrides just pass through via optional chaining (colDef?.field) instead of duplicating the guard. The aggregation result selector now accepts an undefined field and returns null for it, which is correct -- no column means no aggregation result, and it falls through to the guarded util.

I propose leaving the GridParamsApi['getRowValue'] interface as GridColDef to avoid the BC concern you also raised; the internal util is the safety net.

Address review feedback: instead of guarding `colDef` in both the Premium param overrides and the community util, keep the single guard in the util (which is also called directly, e.g. during row-spanning state init, so it must stay defensive) and let the Premium overrides pass through via optional chaining. The aggregation result selector now accepts an `undefined` field and returns `null` for it. Co-Authored-By: Claude Opus 4.8 <[email protected]>

michelengelen

LGTM

…i#22838) Co-authored-by: Claude Opus 4.8 <[email protected]> Co-authored-by: Michel Engelen <[email protected]>

LukasTy added type: bug It doesn't behave as expected. scope: data grid Changes related to the data grid. plan: Pro Impact at least one Pro user. labels Jun 16, 2026

LukasTy self-assigned this Jun 16, 2026

LukasTy mentioned this pull request Jun 16, 2026

[data grid] crash when adding column #22831

Closed

LukasTy and others added 3 commits June 16, 2026 23:49

Merge branch 'master' into claude/flamboyant-pascal-86fd19

8e5da48

Merge branch 'master' into claude/flamboyant-pascal-86fd19

42176c7

LukasTy added the plan: Premium Impact at least one Premium user. label Jun 17, 2026

LukasTy marked this pull request as ready for review June 17, 2026 11:48

LukasTy requested review from MBilalShafi, Copilot and michelengelen June 17, 2026 11:49

Copilot started reviewing on behalf of LukasTy June 17, 2026 11:49 View session

Copilot AI reviewed Jun 17, 2026

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Comment thread packages/x-data-grid/src/hooks/features/rows/gridRowsUtils.ts

Comment thread packages/x-data-grid/src/hooks/features/rows/gridRowSpanningUtils.ts

Comment thread packages/x-data-grid-premium/src/hooks/features/rows/useGridParamsOverridableMethods.ts Outdated

LukasTy requested a review from Copilot June 17, 2026 12:23

Copilot started reviewing on behalf of LukasTy June 17, 2026 12:24 View session

Copilot AI reviewed Jun 17, 2026

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MBilalShafi reviewed Jun 19, 2026

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LukasTy and others added 3 commits June 22, 2026 12:59

Merge branch 'master' into claude/flamboyant-pascal-86fd19

6bec8f2

Merge branch 'master' into claude/flamboyant-pascal-86fd19

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LukasTy requested a review from MBilalShafi June 23, 2026 11:17

michelengelen approved these changes Jun 23, 2026

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michelengelen and others added 3 commits June 23, 2026 16:56

Merge branch 'master' into claude/flamboyant-pascal-86fd19

f0c6b83

Merge branch 'master' into claude/flamboyant-pascal-86fd19

e82411a

Merge branch 'master' into claude/flamboyant-pascal-86fd19

ede5202

LukasTy merged commit 8367e95 into mui:master Jun 24, 2026
21 checks passed

LukasTy deleted the claude/flamboyant-pascal-86fd19 branch June 24, 2026 11:34

mbrookes pushed a commit to mbrookes/mui-x that referenced this pull request Jun 27, 2026

[data grid] Fix crash in getRowValue when colDef is undefined (mu…

a26d965

…i#22838) Co-authored-by: Claude Opus 4.8 <[email protected]> Co-authored-by: Michel Engelen <[email protected]>

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[data grid] Fix crash in `getRowValue` when `colDef` is undefined#22838

[data grid] Fix crash in `getRowValue` when `colDef` is undefined#22838
LukasTy merged 11 commits into
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