Conflict Types Reference

Complete reference for all transformation conflict types detected during projection mapping, including type conversion, truncation, null handling, precision loss, enum narrowing, pattern mismatch, uniqueness, and multi-input conflicts.

April 1, 2026

When a source property is mapped to a target property in a projection, the transformation conflict service analyses the property shapes and detects potential data loss, type incompatibilities, and constraint violations. Each conflict includes a severity level, category, human-readable message, and a set of resolution options.

Conflict Model

export type ConflictSeverity = 'error' | 'warning' | 'info';
export type ConflictCategory = 'type' | 'constraint' | 'multi-input';

export interface Conflict {
  ruleId: string;
  severity: ConflictSeverity;
  category: ConflictCategory;
  message: string;
  resolutionOptions: ResolutionOption[];
}

export interface ResolutionOption {
  id: string;
  label: string;
  requiresInput?: boolean;
  inputLabel?: string;
  inputType?: 'text' | 'select' | 'expression';
  selectOptions?: { label: string; value: string }[];
}

Severity Levels

Severity	Connector Colour	Meaning
error	Red	The mapping will produce incorrect or impossible results without resolution. The architect must choose a resolution strategy before the mapping can be considered complete.
warning	Amber	The mapping may produce data loss or unexpected behaviour. Resolution is recommended but the mapping can proceed.
info	Blue	The mapping is valid but involves a type widening or other notable transformation. No action required.

Conflict Categories

Category	Description
type	Source and target properties have different abstract types. Detected by comparing the type field of each PropertyShape.
constraint	Source and target have the same or compatible types but differ in constraints (maxLength, nullability, value range, enum values, pattern, uniqueness).
multi-input	Multiple source properties map to a single target property. Requires specifying how the values should be combined.

Type Conflicts

Detected when the source and target abstract types differ. The severity depends on the direction of the conversion.

Safe Type Widenings (info)

The following type conversions are considered safe and produce info-level notifications only. No resolution is required.

Source Type	Safe Target Types
integer	string, text, float, decimal
float	string, text, decimal
decimal	string, text
boolean	string, text
date	string, text, datetime
uuid	string, text
enum	string, text

Specific Type Conflict Rules

The following type conversions trigger specific conflict rules with tailored resolution options.

Rule ID	Conversion	Severity	Resolution Options
type-uuid-to-integer	uuid/guid to integer	error	Count (aggregation), Count Distinct, Hash to integer, Custom expression
type-string-to-integer	string to integer	error	Parse (with error handling), Count (aggregation), Custom expression
type-float-to-integer	float to integer	warning	Round, Floor, Ceiling, Truncate
type-decimal-to-float	decimal to float	warning	Accept precision loss, Custom expression
type-datetime-to-date	datetime to date	warning	Truncate time, Accept (time is not meaningful)
type-boolean-to-integer	boolean to integer	info	Standard (true=1, false=0), Custom values
type-json-to-string	json to string	warning	Serialise (JSON.stringify), Extract path (JSON path), Custom expression
type-mismatch	Any other type mismatch	error	Cast to target type, Custom expression

Constraint Conflicts

Detected when source and target have compatible types but constraints that could cause data loss or rejection.

Rule ID	Condition	Severity	Resolution Options
constraint-truncation	Source maxLength exceeds target maxLength	warning	Truncate at target length, Truncate with ellipsis, Reject (fail if exceeds), Use default value
constraint-null-required	Source is nullable but target is required	warning	Default value, Coalesce from another field, Reject nulls (fail pipeline)
constraint-overflow	Source maxValue exceeds target maxValue	warning	Clamp to target max, Reject (fail if exceeds), Use default value, Scale proportionally
constraint-underflow	Source minValue is below target minValue	warning	Clamp to target min, Absolute value, Reject (fail if below), Use default value
constraint-enum-narrowing	Source enum values not present in target enum	warning	Map each value explicitly, Reject unmapped values, Use default for unmapped, Set unmapped to null
constraint-pattern	Target requires a regex pattern the source may not satisfy	warning	Transform to match pattern (expression), Reject non-matching values, Use default for non-matching
constraint-uniqueness	Source is not unique but target requires uniqueness	warning	Deduplicate (keep first), Deduplicate (keep last), Deduplicate (aggregate), Reject duplicates

Multi-Input Conflicts

Detected when more than one source property maps to a single target property. The resolution depends on the target type.

Rule ID	Target Type	Severity	Resolution Options
multi-input-string	string or text	warning	Concatenate with space, Concatenate with comma, Concatenate with custom separator, First non-null, Last non-null, Custom expression
multi-input-numeric	integer, float, or decimal	warning	Sum, Average, Minimum, Maximum, First non-null, Last non-null, Custom expression
multi-input-general	Any other type	warning	First non-null, Last non-null, Custom expression

Resolution Persistence

When an architect resolves a conflict, the resolution is stored on the TransformationMapping in the projection document.

export type ResolutionStatus = 'unresolved' | 'resolved' | 'accepted-as-is';

export interface TransformationResolution {
  status: ResolutionStatus;
  typeConversion?: TypeConversionResolution;
  truncation?: TruncationResolution;
  nullHandling?: NullHandlingResolution;
  precision?: PrecisionResolution;
  enumMapping?: EnumMappingResolution;
  multiSource?: MultiSourceResolution;
  notes?: string;
}

Resolution Sub-Types

Resolution Type	Fields	Used By
TypeConversionResolution	strategy (string), expression (optional string)	type-mismatch, type-string-to-integer, type-json-to-string
TruncationResolution	strategy ('truncate' \| 'ellipsis' \| 'reject' \| 'default'), defaultValue (optional)	constraint-truncation
NullHandlingResolution	strategy ('default' \| 'coalesce' \| 'reject'), defaultValue (optional), coalesceField (optional)	constraint-null-required
PrecisionResolution	strategy ('round' \| 'floor' \| 'ceiling' \| 'truncate' \| 'reject')	type-float-to-integer, type-decimal-to-float
EnumMappingResolution	valueMappings (Record of source to target), unmappedStrategy ('reject' \| 'default' \| 'null' \| 'pass-through'), defaultValue (optional)	constraint-enum-narrowing
MultiSourceResolution	Defined per multi-input conflict resolution	multi-input-string, multi-input-numeric, multi-input-general

Connector Status Indicators

In the projection editor, each mapping connector line displays a visual indicator based on its conflict status.

Status	Visual	Meaning
unresolved-error	Red connector with warning badge	At least one error-severity conflict has no resolution. Requires architect attention.
unresolved-warning	Amber connector with warning badge	At least one warning-severity conflict has no resolution. Resolution recommended.
resolved	Green connector with check badge	All conflicts have been resolved by the architect.
accepted	Green connector with check badge	All conflicts have been explicitly accepted as-is (no changes needed).
clean	Default connector (no badge)	No conflicts detected. Source and target are fully compatible.