feat(assertions): support for conditions (#18577)

Add conditions matcher to assertion package.

Required by #18560.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: robertd

Diff for: packages/@aws-cdk/assertions/README.md

@@ -139,7 +139,7 @@ expect(result.Foo).toEqual({ Value: 'Fred', Description: 'FooFred' });
 expect(result.Bar).toEqual({ Value: 'Fred', Description: 'BarFred' });
 ```
 
-The APIs `hasMapping()` and `findMappings()` provide similar functionalities.
+The APIs `hasMapping()`, `findMappings()`, `hasCondition()`, and `hasCondtions()` provide similar functionalities.
 
 ## Special Matchers
 

Diff for: packages/@aws-cdk/assertions/lib/private/conditions.ts

@@ -0,0 +1,30 @@
+import { filterLogicalId, formatFailure, matchSection } from './section';
+import { Template } from './template';
+
+export function findConditions(template: Template, logicalId: string, props: any = {}): { [key: string]: { [key: string]: any } } {
+  const section: { [key: string] : {} } = template.Conditions;
+  const result = matchSection(filterLogicalId(section, logicalId), props);
+
+  if (!result.match) {
+    return {};
+  }
+
+  return result.matches;
+}
+
+export function hasCondition(template: Template, logicalId: string, props: any): string | void {
+  const section: { [key: string] : {} } = template.Conditions;
+  const result = matchSection(filterLogicalId(section, logicalId), props);
+  if (result.match) {
+    return;
+  }
+
+  if (result.closestResult === undefined) {
+    return 'No conditions found in the template';
+  }
+
+  return [
+    `Template has ${result.analyzedCount} conditions, but none match as expected.`,
+    formatFailure(result.closestResult),
+  ].join('\n');
+}

Diff for: packages/@aws-cdk/assertions/lib/private/template.ts

@@ -4,7 +4,8 @@ export type Template = {
   Resources: { [logicalId: string]: Resource },
   Outputs: { [logicalId: string]: Output },
   Mappings: { [logicalId: string]: Mapping },
-  Parameters: { [logicalId: string]: Parameter }
+  Parameters: { [logicalId: string]: Parameter },
+  Conditions: { [logicalId: string]: Condition },
 }
 
 export type Resource = {
@@ -19,4 +20,6 @@ export type Mapping = { [key: string]: any };
 export type Parameter = {
   Type: string;
   [key: string]: any;
-}
+}
+
+export type Condition = { [key: string]: any };

Diff for: packages/@aws-cdk/assertions/lib/template.ts

@@ -3,6 +3,7 @@ import { Stack, Stage } from '@aws-cdk/core';
 import * as fs from 'fs-extra';
 import { Match } from './match';
 import { Matcher } from './matcher';
+import { findConditions, hasCondition } from './private/conditions';
 import { findMappings, hasMapping } from './private/mappings';
 import { findOutputs, hasOutput } from './private/outputs';
 import { findParameters, hasParameter } from './private/parameters';
@@ -183,6 +184,31 @@ export class Template {
     return findMappings(this.template, logicalId, props);
   }
 
+  /**
+   * Assert that a Condition with the given properties exists in the CloudFormation template.
+   * By default, performs partial matching on the resource, via the `Match.objectLike()`.
+   * To configure different behavour, use other matchers in the `Match` class.
+   * @param logicalId the name of the mapping. Provide `'*'` to match all conditions in the template.
+   * @param props the output as should be expected in the template.
+   */
+  public hasCondition(logicalId: string, props: any): void {
+    const matchError = hasCondition(this.template, logicalId, props);
+    if (matchError) {
+      throw new Error(matchError);
+    }
+  }
+
+  /**
+   * Get the set of matching Conditions that match the given properties in the CloudFormation template.
+   * @param logicalId the name of the condition. Provide `'*'` to match all conditions in the template.
+   * @param props by default, matches all Conditions in the template.
+   * When a literal object is provided, performs a partial match via `Match.objectLike()`.
+   * Use the `Match` APIs to configure a different behaviour.
+   */
+  public findConditions(logicalId: string, props: any = {}): { [key: string]: { [key: string]: any } } {
+    return findConditions(this.template, logicalId, props);
+  }
+
   /**
    * Assert that the CloudFormation template matches the given value
    * @param expected the expected CloudFormation template as key-value pairs.

Diff for: packages/@aws-cdk/assertions/test/template.test.ts

@@ -1,4 +1,4 @@
-import { App, CfnMapping, CfnOutput, CfnParameter, CfnResource, NestedStack, Stack } from '@aws-cdk/core';
+import { App, CfnCondition, CfnMapping, CfnOutput, CfnParameter, CfnResource, Fn, NestedStack, Stack } from '@aws-cdk/core';
 import { Construct } from 'constructs';
 import { Capture, Match, Template } from '../lib';
 
@@ -940,6 +940,150 @@ describe('Template', () => {
       expect(Object.keys(result).length).toEqual(0);
     });
   });
+
+  describe('hasCondition', () => {
+    test('matching', () => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      const inspect = Template.fromStack(stack);
+      expect(() => inspect.hasCondition('*', { 'Fn::Equals': ['Bar', 'Baz'] })).not.toThrow();
+    });
+
+    test('not matching', (done) => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      new CfnCondition(stack, 'Qux', {
+        expression: Fn.conditionNot(Fn.conditionEquals('Quux', 'Quuz')),
+      });
+
+      const inspect = Template.fromStack(stack);
+      expectToThrow(
+        () => inspect.hasCondition('*', {
+          'Fn::Equals': ['Baz', 'Bar'],
+        }),
+        [
+          /2 conditions/,
+          /Missing key/,
+        ],
+        done,
+      );
+      done();
+    });
+
+    test('matching specific outputName', () => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      const inspect = Template.fromStack(stack);
+      expect(() => inspect.hasCondition('Foo', { 'Fn::Equals': ['Bar', 'Baz'] })).not.toThrow();
+    });
+
+    test('not matching specific outputName', (done) => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Baz', 'Bar'),
+      });
+
+      const inspect = Template.fromStack(stack);
+      expectToThrow(
+        () => inspect.hasCondition('Foo', {
+          'Fn::Equals': ['Bar', 'Baz'],
+        }),
+        [
+          /1 conditions/,
+          /Expected Baz but received Bar/,
+        ],
+        done,
+      );
+      done();
+    });
+  });
+
+  describe('findConditions', () => {
+    test('matching', () => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      new CfnCondition(stack, 'Qux', {
+        expression: Fn.conditionNot(Fn.conditionEquals('Quux', 'Quuz')),
+      });
+
+      const inspect = Template.fromStack(stack);
+      const firstCondition = inspect.findConditions('Foo');
+      expect(firstCondition).toEqual({
+        Foo: {
+          'Fn::Equals': [
+            'Bar',
+            'Baz',
+          ],
+        },
+      });
+
+      const secondCondition = inspect.findConditions('Qux');
+      expect(secondCondition).toEqual({
+        Qux: {
+          'Fn::Not': [
+            {
+              'Fn::Equals': [
+                'Quux',
+                'Quuz',
+              ],
+            },
+          ],
+        },
+      });
+    });
+
+    test('not matching', () => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      const inspect = Template.fromStack(stack);
+      const result = inspect.findMappings('Bar');
+      expect(Object.keys(result).length).toEqual(0);
+    });
+
+    test('matching with specific outputName', () => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      const inspect = Template.fromStack(stack);
+      const result = inspect.findConditions('Foo', { 'Fn::Equals': ['Bar', 'Baz'] });
+      expect(result).toEqual({
+        Foo: {
+          'Fn::Equals': [
+            'Bar',
+            'Baz',
+          ],
+        },
+      });
+    });
+
+    test('not matching specific output name', () => {
+      const stack = new Stack();
+      new CfnCondition(stack, 'Foo', {
+        expression: Fn.conditionEquals('Bar', 'Baz'),
+      });
+
+      const inspect = Template.fromStack(stack);
+      const result = inspect.findConditions('Foo', { 'Fn::Equals': ['Bar', 'Qux'] });
+      expect(Object.keys(result).length).toEqual(0);
+    });
+  });
 });
 
 function expectToThrow(fn: () => void, msgs: (RegExp | string)[], done: jest.DoneCallback): void {