Reintroduce the Condition type

This reverts commit ffc2bdc.

Also adds the required ignores for these "breaking" changes to be
accepted, and fixes the one remaining union type.

allowed-breaking-changes.txt

@@ -41,3 +41,8 @@ change-return-type:@aws-cdk/aws-lambda-destinations.LambdaDestination.bind
 change-return-type:@aws-cdk/aws-lambda-destinations.SnsDestination.bind
 change-return-type:@aws-cdk/aws-lambda-destinations.SqsDestination.bind
 removed:@aws-cdk/cdk-assets-schema.DockerImageDestination.imageUri
+incompatible-argument:@aws-cdk/aws-iam.FederatedPrincipal.<initializer>
+incompatible-argument:@aws-cdk/aws-iam.PolicyStatement.addCondition
+incompatible-argument:@aws-cdk/aws-iam.PolicyStatement.addConditions
+incompatible-argument:@aws-cdk/aws-iam.PolicyStatement.addFederatedPrincipal
+incompatible-argument:@aws-cdk/aws-iam.PrincipalPolicyFragment.<initializer>

packages/@aws-cdk/aws-iam/lib/policy-statement.ts

@@ -200,7 +200,7 @@ export class PolicyStatement {
   /**
    * Add a condition to the Policy
    */
-  public addCondition(key: string, value: any) {
+  public addCondition(key: string, value: Condition) {
     const existingValue = this.condition[key];
     this.condition[key] = existingValue ? { ...existingValue, ...value } : value;
   }
@@ -303,6 +303,12 @@ export enum Effect {
   DENY = 'Deny',
 }
 
+/**
+ * Condition for when an IAM policy is in effect. Maps from the keys in a request's context to
+ * a string value or array of string values. See the Conditions interface for more details.
+ */
+export type Condition = Record<string, any>;
+
 /**
  * Conditions for when an IAM Policy is in effect, specified in the following structure:
  *
@@ -313,7 +319,7 @@ export enum Effect {
  * For more information, including which operators are supported, see [the IAM
  * documentation](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html).
  */
-export type Conditions = Record<string, any>;
+export type Conditions = Record<string, Condition>;
 
 /**
  * Interface for creating a policy statement

packages/@aws-cdk/aws-iam/lib/principals.ts

@@ -1,6 +1,6 @@
 import * as cdk from '@aws-cdk/core';
 import { Default, RegionInfo } from '@aws-cdk/region-info';
-import { Conditions, PolicyStatement } from './policy-statement';
+import { Condition, Conditions, PolicyStatement } from './policy-statement';
 import { mergePrincipal } from './util';
 
 /**
@@ -123,7 +123,7 @@ export class PrincipalWithConditions implements IPrincipal {
   /**
    * Add a condition to the principal
    */
-  public addCondition(key: string, value: { [key: string]: any }) {
+  public addCondition(key: string, value: Condition) {
     const existingValue = this.conditions[key];
     this.conditions[key] = existingValue ? { ...existingValue, ...value } : value;
   }