feat(core): Allow multiple criteria when introspecting

src/services/introspector.ts

@@ -23,7 +23,7 @@ export class Introspector {
 
   introspect<R>(
     rule: Rule,
-    criteria: Omit<Constraint, "operator">,
+    criteria: Omit<Constraint, "operator">[],
     subjects: string[]
   ): IntrospectionResult<R>[] {
     // We care about all the possible values for the subjects which will satisfy
@@ -41,7 +41,7 @@ export class Introspector {
       rule.conditions[i] = this.#reverseNoneToAll(rule.conditions[i]);
       rule.conditions[i] = this.#removeIrrelevantConstraints(
         rule.conditions[i],
-        [...subjects, criteria.field]
+        [...subjects, ...criteria.map((c) => c.field)]
       );
     }
 
@@ -374,7 +374,7 @@ export class Introspector {
    */
   #introspectConditions(
     condition: Condition,
-    criteria: Omit<Constraint, "operator">,
+    criteria: Omit<Constraint, "operator">[],
     parentType: keyof Condition = null,
     parentResults: Map<string, Constraint[]> = new Map(),
     depth: number = 0
@@ -601,17 +601,17 @@ export class Introspector {
    */
   protected test(
     candidates: Constraint[],
-    criteria: Omit<Constraint, "operator">,
+    criteria: Omit<Constraint, "operator">[],
     item: Constraint,
     depth: number
   ): boolean {
     // Filter out results which do not match the field of the constraint
     candidates = candidates.filter((r) => r.field === item.field);
 
     // Add the input constraint to the results (if it also matches the field)
-    if (criteria.field === item.field) {
-      candidates.push({ ...criteria, operator: "==" });
-    }
+    criteria.forEach((c) => {
+      if (c.field === item.field) candidates.push({ ...c, operator: "==" });
+    });
 
     // Test that the constraint does not breach the results
     // The test constraint needs to be compared against all the results

src/services/rule-pilot.ts

@@ -93,14 +93,14 @@ export class RulePilot {
    * the possible range of input criteria which would be satisfied by the rule.
    *
    * @param rule The rule to evaluate.
-   * @param constraint The constraint to introspect against.
+   * @param criteria The criteria to introspect against.
    * @param subjects The subjects to introspect for.
    * @throws RuleError if the rule is invalid
    * @throws RuleTypeError if the rule is not granular
    */
   introspect<R = string>(
     rule: Rule,
-    constraint: Omit<Constraint, "operator">,
+    criteria: Omit<Constraint, "operator"> | Omit<Constraint, "operator">[],
     subjects: string[]
   ): IntrospectionResult<R>[] {
     // Before we proceed with the rule, we should validate it.
@@ -109,7 +109,11 @@ export class RulePilot {
       throw new RuleError(validationResult);
     }
 
-    return this.#introspector.introspect<R>(rule, constraint, subjects);
+    return this.#introspector.introspect<R>(
+      rule,
+      Array.isArray(criteria) ? criteria : [criteria],
+      subjects
+    );
   }
 
   /**
@@ -157,17 +161,21 @@ export class RulePilot {
    * the possible range of input criteria which would be satisfied by the rule.
    *
    * @param rule The rule to introspect.
-   * @param constraint The constraint to introspect against.
+   * @param criteria The criteria to introspect against.
    * @param subjects The subjects to introspect for.
    * @throws RuleError if the rule is invalid
    * @throws RuleTypeError if the rule is not granular
    */
   static introspect<R = string>(
     rule: Rule,
-    constraint: Omit<Constraint, "operator">,
+    criteria: Omit<Constraint, "operator"> | Omit<Constraint, "operator">[],
     subjects: string[]
   ): IntrospectionResult<R>[] {
-    return RulePilot.#rulePilot.introspect<R>(rule, constraint, subjects);
+    return RulePilot.#rulePilot.introspect<R>(
+      rule,
+      Array.isArray(criteria) ? criteria : [criteria],
+      subjects
+    );
   }
 
   /**