TBL-005 Cross-column constraints

Overview

Validates that when one column satisfies the when condition, another column satisfies the then constraint. The rule is conditional and is evaluated row by row. Violations are reported as error.

Why it matters

Constraints like “when Status is stable, the Approver column must not be empty” or “when Type is external, the URL column must start with https://” express intra-row conditional consistency that allowed values or regex patterns cannot capture on their own. This rule expresses such relationships between columns.

Options

Field	Type	Required	Description
when	object	Yes	Condition (see below)
then	object	Yes	Constraint (see below)
section	string	—	Restrict validation to tables under a specific section
files	string	—	Glob of files this rule applies to

when (condition)

Field	Type	Description
column	string	Column the condition is evaluated on
equals	string	Triggers when the value equals this string
oneOf	string[]	Triggers when the value is in this array
matches	string	Triggers when the value matches this regex

Specify exactly one of equals / oneOf / matches.

then (constraint)

Field	Type	Description
column	string	Column the constraint is applied to
notEmpty	boolean	Value must not be empty
equals	string	Value must equal this string
oneOf	string[]	Value must be in this array
matches	string	Value must match this regex

Specify exactly one of notEmpty / equals / oneOf / matches.

Bad example

| ID     | Status | Approver |
| ------ | ------ | -------- |
| REQ-01 | stable | alice    |
| REQ-02 | stable |          |

With when: { column: "Status", equals: "stable" } and then: { column: "Approver", notEmpty: true }, the row whose Status is stable but whose Approver is empty triggers a violation.

docs/requirements.md
  line 4  error  Row where Status="stable": column "Approver" must not be empty  TBL-005

After fix

| ID     | Status | Approver |
| ------ | ------ | -------- |
| REQ-01 | stable | alice    |
| REQ-02 | stable | bob      |

Configuration example

{
  "rule": "tbl005",
  "options": {
    "when": { "column": "Status", "equals": "stable" },
    "then": { "column": "Approver", "notEmpty": true }
  }
}

Related rules

• TBL-003 Allowed values — Single-column value constraints
• TBL-004 Cell pattern — Single-column pattern constraints