Fix an issue where overwriting a non-computed cell caused the Value of the formula cell is not computed error (#1569)

* Add unit tests reproducing the bug

* Fix the error

* Improve test utils log message for columnIndexToSheet function

* Add jsdoc comments to Operations.ts file

Author: sequba

CHANGELOG.md

@@ -7,6 +7,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed an issue where overwriting a non-computed cell caused the `Value of the formula cell is not computed` error. [#1194](https://github.com/handsontable/hyperformula/issues/1194)
+
 ## [3.1.0] - 2025-10-14
 
 ### Changed

src/Operations.ts

@@ -22,10 +22,10 @@ import {
   ParsingErrorVertex,
   SheetMapping,
   SparseStrategy,
-  ValueCellVertex
+  ValueCellVertex,
 } from './DependencyGraph'
 import { FormulaVertex } from './DependencyGraph/FormulaCellVertex'
-import { RawAndParsedValue } from './DependencyGraph/ValueCellVertex'
+import { RawAndParsedValue, ValueCellVertexValue } from './DependencyGraph/ValueCellVertex'
 import { AddColumnsTransformer } from './dependencyTransformers/AddColumnsTransformer'
 import { AddRowsTransformer } from './dependencyTransformers/AddRowsTransformer'
 import { CleanOutOfScopeDependenciesTransformer } from './dependencyTransformers/CleanOutOfScopeDependenciesTransformer'
@@ -459,8 +459,6 @@ export class Operations {
 
   /**
    * Restores a single cell.
-   * @param {SimpleCellAddress} address
-   * @param {ClipboardCell} clipboardCell
    */
   public restoreCell(address: SimpleCellAddress, clipboardCell: ClipboardCell): void {
     switch (clipboardCell.type) {
@@ -570,7 +568,6 @@ export class Operations {
 
           this.setFormulaToCell(address, size, parserResult)
         } catch (error) {
-
           if (!(error as Error).message) {
             throw error
           }
@@ -598,45 +595,66 @@ export class Operations {
     }
   }
 
+  /**
+   * Sets cell content to an instance of parsing error.
+   * Creates a ParsingErrorVertex and updates the dependency graph and column search index.
+   */
   public setParsingErrorToCell(rawInput: string, errors: ParsingError[], address: SimpleCellAddress) {
-    const oldValue = this.dependencyGraph.getCellValue(address)
+    this.removeCellValueFromColumnSearch(address)
+
     const vertex = new ParsingErrorVertex(errors, rawInput)
     const arrayChanges = this.dependencyGraph.setParsingErrorToCell(address, vertex)
-    this.columnSearch.remove(getRawValue(oldValue), address)
+
     this.columnSearch.applyChanges(arrayChanges.getChanges())
     this.changes.addAll(arrayChanges)
     this.changes.addChange(vertex.getCellValue(), address)
   }
 
+  /**
+   * Sets cell content to a formula.
+   * Creates a FormulaCellVertex and updates the dependency graph and column search index.
+   */
   public setFormulaToCell(address: SimpleCellAddress, size: ArraySize, {
     ast,
     hasVolatileFunction,
     hasStructuralChangeFunction,
     dependencies
   }: ParsingResult) {
-    const oldValue = this.dependencyGraph.getCellValue(address)
+    this.removeCellValueFromColumnSearch(address)
+
     const arrayChanges = this.dependencyGraph.setFormulaToCell(address, ast, absolutizeDependencies(dependencies, address), size, hasVolatileFunction, hasStructuralChangeFunction)
-    this.columnSearch.remove(getRawValue(oldValue), address)
+
     this.columnSearch.applyChanges(arrayChanges.getChanges())
     this.changes.addAll(arrayChanges)
   }
 
+  /**
+   * Sets cell content to a value.
+   * Creates a ValueCellVertex and updates the dependency graph and column search index.
+   */
   public setValueToCell(value: RawAndParsedValue, address: SimpleCellAddress) {
-    const oldValue = this.dependencyGraph.getCellValue(address)
+    this.changeCellValueInColumnSearch(address, value.parsedValue)
+
     const arrayChanges = this.dependencyGraph.setValueToCell(address, value)
-    this.columnSearch.change(getRawValue(oldValue), getRawValue(value.parsedValue), address)
+
     this.columnSearch.applyChanges(arrayChanges.getChanges().filter(change => !equalSimpleCellAddress(change.address, address)))
     this.changes.addAll(arrayChanges)
     this.changes.addChange(value.parsedValue, address)
   }
 
+  /**
+   * Sets cell content to an empty value.
+   * Creates an EmptyCellVertex and updates the dependency graph and column search index.
+   */
   public setCellEmpty(address: SimpleCellAddress) {
     if (this.dependencyGraph.isArrayInternalCell(address)) {
       return
     }
-    const oldValue = this.dependencyGraph.getCellValue(address)
+
+    this.removeCellValueFromColumnSearch(address)
+
     const arrayChanges = this.dependencyGraph.setCellEmpty(address)
-    this.columnSearch.remove(getRawValue(oldValue), address)
+
     this.columnSearch.applyChanges(arrayChanges.getChanges())
     this.changes.addAll(arrayChanges)
     this.changes.addChange(EmptyValue, address)
@@ -923,6 +941,45 @@ export class Operations {
     }
     return this.dependencyGraph.fetchCellOrCreateEmpty(expression.address).vertex
   }
+
+  /**
+   * Removes a cell value from the columnSearch index.
+   * Ignores the non-computed formula vertices.
+   */
+  private removeCellValueFromColumnSearch(address: SimpleCellAddress): void {
+    if (this.isNotComputed(address)) {
+      return
+    }
+
+    const oldValue = this.dependencyGraph.getCellValue(address)
+    this.columnSearch.remove(getRawValue(oldValue), address)
+  }
+
+  /**
+   * Changes a cell value in the columnSearch index.
+   * Ignores the non-computed formula vertices.
+   */
+  private changeCellValueInColumnSearch(address: SimpleCellAddress, newValue: ValueCellVertexValue): void {
+    if (this.isNotComputed(address)) {
+      return
+    }
+
+    const oldValue = this.dependencyGraph.getCellValue(address)
+    this.columnSearch.change(getRawValue(oldValue), getRawValue(newValue), address)
+  }
+
+  /**
+   * Checks if the FormulaCellVertex or ArrayVertex at the given address is not computed.
+   */
+  private isNotComputed(address: SimpleCellAddress): boolean {
+    const vertex = this.dependencyGraph.getCell(address)
+
+    if (!vertex) {
+      return false
+    }
+
+    return 'isComputed' in vertex && !vertex.isComputed()
+  }
 }
 
 export function normalizeRemovedIndexes(indexes: ColumnRowIndex[]): ColumnRowIndex[] {

test/unit/column-index.spec.ts

@@ -14,7 +14,8 @@ import {ColumnIndex} from '../../src/Lookup/ColumnIndex'
 import {NamedExpressions} from '../../src/NamedExpressions'
 import {ColumnsSpan, RowsSpan} from '../../src/Span'
 import {Statistics} from '../../src/statistics'
-import {adr, expectColumnIndexToMatchSheet} from './testUtils'
+import {adr, detailedError, expectColumnIndexToMatchSheet} from './testUtils'
+import { ErrorMessage } from '../../src/error-message'
 
 function buildEmptyIndex(transformingService: LazilyTransformingAstService, config: Config, statistics: Statistics): ColumnIndex {
   const functionRegistry = new FunctionRegistry(config)
@@ -600,6 +601,8 @@ describe('Arrays', () => {
 
     engine.setCellContents(adr('D1'), [['foo']])
 
+    expect(engine.getCellValue(adr('C1'))).toEqualError(detailedError(ErrorType.SPILL, ErrorMessage.NoSpaceForArrayResult))
+
     expectColumnIndexToMatchSheet([
       [1, 2, null, 'foo']
     ], engine)

test/unit/computation-suspension.spec.ts

@@ -206,4 +206,22 @@ describe('Evaluation suspension', () => {
     expect(changes).toContainEqual(new ExportedCellChange(adr('B1'), 4))
     expect(changes).toContainEqual(new ExportedCellChange(adr('C1'), 5))
   })
+
+  it('allows to update cell content of a not computed formula cell (#1194)', () => {
+    const hf = HyperFormula.buildFromArray([], {
+      licenseKey: 'gpl-v3'
+    })
+
+    hf.suspendEvaluation()
+    hf.setCellContents(adr('A1'), '=42')
+    hf.setCellContents(adr('A1'), 42)
+    hf.setCellContents(adr('A1'), '=42')
+    hf.setCellContents(adr('A1'), null)
+    hf.setCellContents(adr('A1'), '=42')
+    hf.setCellContents(adr('A1'), '==')
+    hf.setCellContents(adr('A1'), '=42')
+    hf.setCellContents(adr('A1'), '=42')
+    hf.resumeEvaluation()
+    expect(hf.getCellValue(adr('A1'))).toBe(42)
+  })
 })

test/unit/rebuild.spec.ts

@@ -53,4 +53,14 @@ describe('Rebuilding engine', () => {
 
     expect(rebuildEngineSpy).toHaveBeenCalled()
   })
+
+  it('doesn\'t throw after adding named expression (#1194)', () => {
+    const hf = HyperFormula.buildFromArray([['=42']], {
+      licenseKey: 'gpl-v3'
+    })
+
+
+    hf.addNamedExpression('ABC', '=Sheet1!$A$1')
+    expect(() => hf.rebuildAndRecalculate()).not.toThrow()
+  })
 })

test/unit/testUtils.ts

@@ -213,7 +213,7 @@ export function columnIndexToSheet(columnIndex: ColumnIndex, width: number, heig
       for (const row of index) {
         result[row] = result[row] ?? []
         if (result[row][col] !== undefined) {
-          throw new Error('ColumnIndex ambiguity.')
+          throw new Error(`ColumnIndex ambiguity. Expected ${JSON.stringify(result[row][col])}, but found ${JSON.stringify(value)} at row ${JSON.stringify(row)}, column ${JSON.stringify(col)}`)
         }
         result[row][col] = value
       }

test/unit/update-config.spec.ts

@@ -112,4 +112,14 @@ describe('update config', () => {
     engine.updateConfig({ useColumnIndex: false, functionArgSeparator: ',', undoLimit: 20 })
     expect(rebuildEngineSpy).not.toHaveBeenCalled()
   })
+
+  it('doesn\'t throw after adding named expression (#1194)', () => {
+    const hf = HyperFormula.buildFromArray([['=42']], {
+      licenseKey: 'gpl-v3'
+    })
+
+
+    hf.addNamedExpression('ABC', '=Sheet1!$A$1')
+    expect(() => hf.updateConfig({ maxRows: 101 })).not.toThrow()
+  })
 })