Static analysis - GoRules Documentation

GoRules continuously analyses every graph and policy as you edit - no run required. Findings appear in the document’s Problems tab, on the Quality Control page, and as a pre-flight check when you save.

Problems tab showing PREFER_DICTIONARY hints on decision table output columns, with explanations and suggested fixes — The Problems tab with two findings and suggested fixes

Each finding has a severity:

Severity	Meaning
Error	The document will misbehave or fail to evaluate. Fix before shipping.
Warning	Likely a mistake, but evaluation still works.
Hint	A quality suggestion. Hints appear in the Problems tab (toggleable) but not on Quality Control.

Static analysis needs to know your types. A graph whose input node has no schema - or an empty one - reports MISSING_INPUT_SCHEMA and skips deeper checks until you define one in the Interface tab.

Names and types

Code	What it means
`UNDEFINED_VARIABLE`	An expression references a property that nothing declares or computes. Usually a typo or a missing data model property.
`TYPE_MISMATCH`	A value doesn’t match the expected type - often an optional value used in arithmetic without a fallback, or a typed table cell with the wrong kind of value.
`INVALID_EXPRESSION`	The expression doesn’t evaluate against the resolved types.
`PARSE_ERROR`	The expression isn’t valid ZEN syntax.
`IMPLICIT_ANY`	A schema leaf has no type, so it resolves to `any` and can’t be checked. Give it a concrete type.
`INVALID_NAME`	An identifier contains dots, brackets, or whitespace, or starts with a digit.
`UNRESOLVED_FUNCTION_TYPE`	A function’s return type can’t be determined.
`MAX_DEPTH_EXCEEDED`	Nesting exceeds the analyser’s depth limit.

Writes and dependencies

Code	What it means
`DUPLICATE_WRITER`	Two blocks write the same property. Checked across a policy’s whole import group - the conflict can be in another file.
`CYCLIC_DEPENDENCY`	Rules depend on each other in a loop, so no valid order exists.
`SELF_REFERENCING_WRITE`	A block writes a property it also reads.
`INPUT_OVERRIDE`	A rule overwrites a property declared as input.
`INVALID_WRITE_PATH`	The write target isn’t a valid property path.
`PARTIAL_OBJECT_WRITE`	A block writes part of an object another block writes whole.
`MIXED_SCOPE`	One block writes multiple entities, or mixes entity and global writes. Split it.
`UNREACHABLE_ENTITY_READ`	A block reads an entity no execution path can populate.

Data models, dictionaries, and imports

Code	What it means
`DATA_MODEL_COLLISION`	The same entity is declared twice with different shapes, or an entity, global, and dictionary share a name.
`UNKNOWN_DATA_MODEL_TARGET`	A reference points at a name that is neither an entity nor a dictionary.
`DUPLICATE_PROPERTY`	A data model declares the same property twice.
`DUPLICATE_ENUM_VALUE`	A dictionary contains the same value twice.
`IMPORT_NOT_FOUND`	An imported policy path doesn’t resolve to a document.
`CIRCULAR_IMPORT`	Policies import each other in a cycle.

Structure and completeness

Code	What it means
`EMPTY_BLOCK`	A block has no content. An error on assertions; a warning on empty tables, matches, and expressions.
`MISSING_DEFAULT_BRANCH`	A match has no branch for the remaining cases.
`UNSUPPORTED_NESTED_ITERATION`	Iteration nested deeper than the engine supports.
`INVALID_GRAPH_STRUCTURE`	The graph’s nodes and edges don’t form a valid flow.
`UNREACHABLE_NODE`	A node no path from the input can reach.
`MISSING_INPUT_SCHEMA`	The graph’s input node has no usable schema; deeper checks are skipped.
`UNCHECKED_NODE`	A node the analyser couldn’t verify.
`NULLABILITY_DIVERGENCE`	A value’s nullability differs between paths that later join.

Quality hints

Hints don’t indicate bugs - they point at rules that could be simpler, safer, or easier to maintain.

Code	Suggestion
`REDUNDANT_NULLISH`	A `??` fallback on a value that is never null - dead code; remove the fallback.
`REPEATED_DERIVATION`	The same sub-expression is computed in several places. Compute it once and reference it.
`PREFER_MATCH`	A construct that would read better as a match block.
`PREFER_DICTIONARY`	An inline set of fixed values that should be a named dictionary - you get membership checking and labels for free.
`REDUNDANT_TABLE_ROW`	A decision table row that can never produce a distinct outcome.
`NON_DISCRIMINATING_COLUMN`	A table column that never affects which row matches.
`REDUNDANT_PARENTHESES`	Parentheses that don’t change evaluation.

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