{"record":{"id":"44ef49d48fe93b94","repo":"grafana/k6","slug":"evaluate-requires-a-page-function-44ef49","errorCode":null,"errorMessage":"evaluate requires a page function","messagePattern":"evaluate requires a page function","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"internal/js/modules/k6/browser/browser/page_mapping.go","lineNumber":107,"sourceCode":"\t\t\t}), nil\n\t\t},\n\t\t\"emulateMedia\": func(opts sobek.Value) (*sobek.Promise, error) {\n\t\t\tpopts, err := parsePageEmulateMediaOptions(rt, opts, common.NewPageEmulateMediaOptions(p))\n\t\t\tif err != nil {\n\t\t\t\treturn nil, fmt.Errorf(\"parsing emulateMedia options: %w\", err)\n\t\t\t}\n\t\t\treturn promise(vu, func() (any, error) {\n\t\t\t\treturn nil, p.EmulateMedia(popts) //nolint:wrapcheck\n\t\t\t}), nil\n\t\t},\n\t\t\"emulateVisionDeficiency\": func(typ string) *sobek.Promise {\n\t\t\treturn promise(vu, func() (any, error) {\n\t\t\t\treturn nil, p.EmulateVisionDeficiency(typ) //nolint:wrapcheck\n\t\t\t})\n\t\t},\n\t\t\"evaluate\": func(pageFunc sobek.Value, gargs ...sobek.Value) (*sobek.Promise, error) {\n\t\t\tif sobekEmptyString(pageFunc) {\n\t\t\t\treturn nil, fmt.Errorf(\"evaluate requires a page function\")\n\t\t\t}\n\t\t\tfuncString := pageFunc.String()\n\t\t\tgopts := exportArgs(gargs)\n\t\t\treturn promise(vu, func() (any, error) {\n\t\t\t\treturn p.Evaluate(funcString, gopts...)\n\t\t\t}), nil\n\t\t},\n\t\t\"evaluateHandle\": func(pageFunc sobek.Value, gargs ...sobek.Value) (*sobek.Promise, error) {\n\t\t\tif sobekEmptyString(pageFunc) {\n\t\t\t\treturn nil, fmt.Errorf(\"evaluateHandle requires a page function\")\n\t\t\t}\n\t\t\tfuncString := pageFunc.String()\n\t\t\tgopts := exportArgs(gargs)\n\t\t\treturn promise(vu, func() (any, error) {\n\t\t\t\tjsh, err := p.EvaluateHandle(funcString, gopts...)\n\t\t\t\tif err != nil {\n\t\t\t\t\treturn nil, err //nolint:wrapcheck\n\t\t\t\t}","sourceCodeStart":89,"sourceCodeEnd":125,"githubUrl":"https://github.com/grafana/k6/blob/93accf6570dcd306ca5e99cc44c393ee3797761b/internal/js/modules/k6/browser/browser/page_mapping.go#L89-L125","documentation":"Error \"evaluate requires a page function\" thrown in grafana/k6.","triggerScenarios":"Thrown at internal/js/modules/k6/browser/browser/page_mapping.go:107 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"93accf6570dcd306ca5e99cc44c393ee3797761b","analyzedAt":"2026-08-15T21:23:27.118Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}