chore: enforce consistent type imports and exports

.projenrc.ts

@@ -78,4 +78,10 @@ project.npmignore?.exclude('/scripts/', '.projenrc.ts');
 // cdklabs-projen-project-types is overzealous about adding this dependency
 project.deps.removeDependency('constructs');
 
+// modern type imports/exports
+project.eslint?.addRules({
+  '@typescript-eslint/consistent-type-exports': 'error',
+  '@typescript-eslint/consistent-type-imports': 'error',
+});
+
 project.synth();

src/construct.ts

@@ -1,5 +1,6 @@
-import { Dependable, IDependable } from './dependency';
-import { MetadataEntry } from './metadata';
+import type { IDependable } from './dependency';
+import { Dependable } from './dependency';
+import type { MetadataEntry } from './metadata';
 import { captureStackTrace } from './private/stack-trace';
 import { addressOf } from './private/uniqueid';
 

src/dependency.ts

@@ -1,4 +1,4 @@
-import { IConstruct } from './construct';
+import type { IConstruct } from './construct';
 
 /**
  * Trait marker for classes that can be depended upon

src/index.ts

@@ -1,3 +1,3 @@
 export * from './construct';
-export * from './metadata';
+export type * from './metadata';
 export * from './dependency';

test/construct.test.ts

@@ -1,5 +1,6 @@
 import { App as Root } from './util';
-import { Construct, ConstructOrder, DependencyGroup, Dependable, IConstruct } from '../src';
+import type { IConstruct } from '../src';
+import { Construct, ConstructOrder, DependencyGroup, Dependable } from '../src';
 
 // tslint:disable:variable-name
 // tslint:disable:max-line-length