{"record":{"id":"da47bd721da57f6a","repo":"robfig/cron","slug":"empty-spec-string","errorCode":null,"errorMessage":"empty spec string","messagePattern":"empty spec string","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"parser.go","lineNumber":90,"sourceCode":"\toptionals := 0\n\tif options&DowOptional > 0 {\n\t\toptionals++\n\t}\n\tif options&SecondOptional > 0 {\n\t\toptionals++\n\t}\n\tif optionals > 1 {\n\t\tpanic(\"multiple optionals may not be configured\")\n\t}\n\treturn Parser{options}\n}\n\n// Parse returns a new crontab schedule representing the given spec.\n// It returns a descriptive error if the spec is not valid.\n// It accepts crontab specs and features configured by NewParser.\nfunc (p Parser) Parse(spec string) (Schedule, error) {\n\tif len(spec) == 0 {\n\t\treturn nil, fmt.Errorf(\"empty spec string\")\n\t}\n\n\t// Extract timezone if present\n\tvar loc = time.Local\n\tif strings.HasPrefix(spec, \"TZ=\") || strings.HasPrefix(spec, \"CRON_TZ=\") {\n\t\tvar err error\n\t\ti := strings.Index(spec, \" \")\n\t\teq := strings.Index(spec, \"=\")\n\t\tif loc, err = time.LoadLocation(spec[eq+1 : i]); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"provided bad location %s: %v\", spec[eq+1:i], err)\n\t\t}\n\t\tspec = strings.TrimSpace(spec[i:])\n\t}\n\n\t// Handle named schedules (descriptors), if configured\n\tif strings.HasPrefix(spec, \"@\") {\n\t\tif p.options&Descriptor == 0 {\n\t\t\treturn nil, fmt.Errorf(\"parser does not accept descriptors: %v\", spec)","sourceCodeStart":72,"sourceCodeEnd":108,"githubUrl":"https://github.com/robfig/cron/blob/bc59245fe10efaed9d51b56900192527ed733435/parser.go#L72-L108","documentation":"Parse rejects an empty spec string before doing any parsing. A cron schedule expression must contain at least one field, so an empty input is immediately invalid and returned as an error rather than a schedule.","triggerScenarios":"Calling Parser.Parse(\"\") — e.g. spec read from an empty config value, environment variable, or untrimmed whitespace that was stripped to nothing.","commonSituations":"Config files or env vars where CRON_SPEC= is unset; YAML/JSON config with a blank string value passed straight to Parse; trimming user input down to zero length.","solutions":["Check len(strings.TrimSpace(spec)) > 0 before calling Parse","Provide a default schedule when the spec is empty","Return a friendlier validation error to the user before invoking Parse"],"exampleFix":"// before\nsched, err := parser.Parse(cfg.Spec)\n// after\nif strings.TrimSpace(cfg.Spec) == \"\" {\n    return nil, fmt.Errorf(\"cron spec is required\")\n}\nsched, err := parser.Parse(cfg.Spec)","handlingStrategy":"validation","validationCode":"if strings.TrimSpace(spec) == \"\" {\n\treturn nil, errors.New(\"cron spec must not be empty\")\n}","typeGuard":null,"tryCatchPattern":"sched, err := parser.Parse(spec)\nif err != nil {\n\treturn fmt.Errorf(\"invalid cron spec %q: %w\", spec, err)\n}","preventionTips":["Trim and check config/env values before parsing","Fail fast at config-load time on empty schedules","Provide sensible default schedules for optional config"],"tags":["go","cron","validation","empty-input"],"backgroundTag":"empty-required-field","analyzedSha":"bc59245fe10efaed9d51b56900192527ed733435","analyzedAt":"2026-09-07T00:35:06.760Z","contentChangedAt":"2026-09-07T00:35:06.760Z","schemaVersion":2},"datasetVersion":"2026-09-16T04:17:20.429Z"}