{"record":{"id":"08f822ce8bf0e6eb","repo":"instructure/canvas-lms","slug":"peer-review-override-available-from-date-cannot-be-before","errorCode":null,"errorMessage":"Peer review override available from date cannot be before parent override due date","messagePattern":"Peer review override available from date cannot be before parent override due date","errorType":"validation","errorClass":"PeerReview::InvalidDatesError","httpStatus":null,"severity":"error","filePath":"app/services/peer_review/validations.rb","lineNumber":162,"sourceCode":"    end\n  end\n\n  def validate_dates_within_parent_boundaries(child_dates:, parent_unlock_at:, parent_due_at:, parent_lock_at:, is_override: false)\n    child_unlock_at = parse_date(child_dates, :unlock_at)\n    child_due_at = parse_date(child_dates, :due_at)\n    child_lock_at = parse_date(child_dates, :lock_at)\n\n    # Validate: parent unlock_at <= parent due_at\n    if parent_unlock_at && parent_due_at && parent_unlock_at > parent_due_at\n      raise PeerReview::InvalidDatesError,\n            is_override ? I18n.t(\"Parent override due date cannot be before parent override available from date\") : I18n.t(\"Assignment due date cannot be before assignment available from date\")\n    end\n\n    # Validate: child unlock_at constraint\n    # If parent_due_at is present, validate: parent due_at <= child unlock_at\n    # Otherwise, fall back to: parent unlock_at <= child unlock_at\n    if parent_due_at && child_unlock_at && parent_due_at > child_unlock_at\n      raise PeerReview::InvalidDatesError,\n            is_override ? I18n.t(\"Peer review override available from date cannot be before parent override due date\") : I18n.t(\"Peer review available from date cannot be before assignment due date\")\n    elsif !parent_due_at && parent_unlock_at && child_unlock_at && parent_unlock_at > child_unlock_at\n      raise PeerReview::InvalidDatesError,\n            is_override ? I18n.t(\"Peer review override available from date cannot be before parent override available from date\") : I18n.t(\"Peer review available from date cannot be before assignment available from date\")\n    end\n\n    # Validate: parent unlock_at <= child due_at (for backward compatibility)\n    if parent_unlock_at && child_due_at && parent_unlock_at > child_due_at\n      raise PeerReview::InvalidDatesError,\n            is_override ? I18n.t(\"Peer review override due date cannot be before parent override available from date\") : I18n.t(\"Peer review due date cannot be before assignment available from date\")\n    end\n\n    # Validate: parent due_at <= child due_at\n    if parent_due_at && child_due_at && parent_due_at > child_due_at\n      raise PeerReview::InvalidDatesError,\n            is_override ? I18n.t(\"Peer review override due date cannot be before parent override due date\") : I18n.t(\"Peer review due date cannot be before assignment due date\")\n    end\n","sourceCodeStart":144,"sourceCodeEnd":180,"githubUrl":"https://github.com/instructure/canvas-lms/blob/1c9f0bb8013ed69c4f2efe11fd483025469b7e6c/app/services/peer_review/validations.rb#L144-L180","documentation":"PeerReview::InvalidDatesError raised by validate_dates_within_parent_boundaries when the peer review's available-from date starts before the parent is even due. Canvas requires assignment due_at <= peer review unlock_at (peer reviews open only after the assignment is due). When the parent has a due_at, the message compares against it; the elsif branch (line 165, error 565) covers the fallback to parent unlock_at.","triggerScenarios":"Calling validate_peer_review_dates_against_parent_assignment with parent assignment due_at later than the peer review unlock_at, or validate_override_dates_against_parent_override where parent_due_at (due_at_overridden) > peer review override unlock_at. E.g. assignment due 2026-05-10, peer review unlock 2026-05-01.","commonSituations":"Scripts that copy the same unlock date to both assignment and peer review; teachers scheduling reviews to run alongside the assignment; override flows where the parent override due was extended after peer review dates were drafted.","solutions":["Set the peer review unlock_at to a timestamp >= parent assignment due_at","Or move the parent assignment due_at earlier so reviews can open when intended","If the parent should have no due gate, set parent due_at to nil so validation falls back to comparing against parent unlock_at","Pre-validate: raise if parent.due_at && pr.due_at_pr... i.e. raise if parent.due_at > pr_unlock_at"],"exampleFix":"// before\nassignment.update(due_at: '2026-05-10T00:00:00Z')\npeer_review_dates = { unlock_at: '2026-05-01T00:00:00Z' }\n// after\nassignment.update(due_at: '2026-05-10T00:00:00Z')\npeer_review_dates = { unlock_at: '2026-05-10T00:00:01Z' }","handlingStrategy":"validation","validationCode":"def reviews_open_after_assignment_due?(parent, pr_dates)\n  return true if parent.due_at.nil? || pr_dates[:unlock_at].nil?\n  parent.due_at <= Time.zone.parse(pr_dates[:unlock_at].to_s)\nend","typeGuard":null,"tryCatchPattern":"begin\n  validator.validate_peer_review_dates_against_parent_assignment(pr_dates, assignment)\nrescue PeerReview::InvalidDatesError => e\n  if e.message.include?('available from date cannot be before')\n    pr_dates[:unlock_at] = assignment.due_at + 1.minute\n    retry\n  end\n  raise\nend","preventionTips":["Default peer review unlock_at to assignment due_at (or shortly after)","Remember the invariant: assignment due <= review unlock <= review due <= review lock <= assignment lock","When extending an assignment due date, re-run peer review date validation afterward","Display the required date chain in UIs to prevent invalid manual entry"],"tags":["peer-review","date-validation","parent-assignment","canvas-lms"],"backgroundTag":"invalid-argument-value","analyzedSha":"1c9f0bb8013ed69c4f2efe11fd483025469b7e6c","analyzedAt":"2026-09-15T20:33:18.891Z","contentChangedAt":"2026-09-15T20:33:18.891Z","schemaVersion":2},"datasetVersion":"2026-09-23T02:17:17.105Z"}