feat(heritage): Add support for interface heritage

This enables converting interfaces extending other interfaces from typescript:

interface A extends B { ... }

To in core-types let A become an and-type of ref B and an object.

Reconstruction backwards works too.

lib/__snapshots__/core-types-to-ts.test.ts.snap

@@ -1,5 +1,64 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`core-types-to-ts and-type as empty interface with 1 heritage 1`] = `
+"export interface foo extends bar {
+}
+
+export interface bar {
+    b: number;
+}
+"
+`;
+
+exports[`core-types-to-ts and-type as empty interface with 2 heritage 1`] = `
+"export interface foo extends bar, baz {
+}
+
+export interface bar {
+    b: number;
+}
+
+export interface baz {
+    z: boolean;
+}
+"
+`;
+
+exports[`core-types-to-ts and-type as non-empty interface with 1 heritage 1`] = `
+"export interface foo extends bar {
+    f: string;
+}
+
+export interface bar {
+    b: number;
+}
+"
+`;
+
+exports[`core-types-to-ts and-type as non-empty interface with 2 heritage 1`] = `
+"export interface foo extends bar, baz {
+    f: string;
+}
+
+export interface bar {
+    b: number;
+}
+
+export interface baz {
+    z: boolean;
+}
+"
+`;
+
+exports[`core-types-to-ts and-type that cannot be an interface because non-object ref 1`] = `
+"export type foo = {
+    f?: string;
+} & bar;
+
+export type bar = null;
+"
+`;
+
 exports[`core-types-to-ts complex type 1`] = `
 {
   "convertedTypes": [

lib/bi-directional.test.ts

@@ -175,6 +175,49 @@ export type Bak = 17;
 `export type Foo_Bar_Baz = 42;
 
 export type Bak = 17;
+`
+		);
+	} );
+
+	it( "handle extending two interfaces (include-if-referenced)", ( ) =>
+	{
+		const coreTypes = convertTypeScriptToCoreTypes(
+			`
+				interface A {
+					a: 'a';
+				}
+				export interface B {
+					b: 'b';
+				}
+				export interface C extends A, B {
+					c: 'c';
+				}
+			`,
+			{
+				nonExported: 'include-if-referenced'
+			}
+		);
+
+		const ts = convertCoreTypesToTypeScript(
+			coreTypes.data,
+			{
+				noDescriptiveHeader: true,
+				noDisableLintHeader: true,
+			}
+		);
+
+		expect( ts.data ).toBe(
+`export interface B {
+    b: "b";
+}
+
+export interface C extends A, B {
+    c: "c";
+}
+
+export interface A {
+    a: "a";
+}
 `
 		);
 	} );

lib/core-types-to-ts.test.ts

@@ -280,4 +280,195 @@ describe( "core-types-to-ts", ( ) =>
 
 		expect( ts.data ).toMatchSnapshot( );
 	} );
+
+	it( "and-type that cannot be an interface because non-object ref", ( ) =>
+	{
+		const ts = convertCoreTypesToTypeScript( wrapDocument( [
+			{
+				name: 'foo',
+				type: 'and',
+				and: [
+					{
+						type: 'object',
+						properties: {
+							f: { required: false, node: { type: 'string' } },
+						},
+						additionalProperties: false,
+					},
+					{
+						type: 'ref',
+						ref: 'bar',
+					},
+				],
+			},
+			{
+				name: 'bar',
+				type: 'null',
+			},
+		] ),
+		{ noDescriptiveHeader: true, noDisableLintHeader: true }
+		);
+
+		expect( ts.data ).toMatchSnapshot( );
+	} );
+
+	it( "and-type as empty interface with 1 heritage", ( ) =>
+	{
+		const ts = convertCoreTypesToTypeScript( wrapDocument( [
+			{
+				name: 'foo',
+				type: 'and',
+				and: [
+					{
+						type: 'object',
+						properties: { },
+						additionalProperties: false,
+					},
+					{
+						type: 'ref',
+						ref: 'bar',
+					},
+				],
+			},
+			{
+				name: 'bar',
+				type: 'object',
+				properties: {
+					b: { required: true, node: { type: 'number' } },
+				},
+				additionalProperties: false,
+			},
+		] ),
+		{ noDescriptiveHeader: true, noDisableLintHeader: true }
+		);
+
+		expect( ts.data ).toMatchSnapshot( );
+	} );
+
+	it( "and-type as empty interface with 2 heritage", ( ) =>
+	{
+		const ts = convertCoreTypesToTypeScript( wrapDocument( [
+			{
+				name: 'foo',
+				type: 'and',
+				and: [
+					{
+						type: 'object',
+						properties: { },
+						additionalProperties: false,
+					},
+					{
+						type: 'ref',
+						ref: 'bar',
+					},
+					{
+						type: 'ref',
+						ref: 'baz',
+					},
+				],
+			},
+			{
+				name: 'bar',
+				type: 'object',
+				properties: {
+					b: { required: true, node: { type: 'number' } },
+				},
+				additionalProperties: false,
+			},
+			{
+				name: 'baz',
+				type: 'object',
+				properties: {
+					z: { required: true, node: { type: 'boolean' } },
+				},
+				additionalProperties: false,
+			},
+		] ),
+		{ noDescriptiveHeader: true, noDisableLintHeader: true }
+		);
+
+		expect( ts.data ).toMatchSnapshot( );
+	} );
+
+	it( "and-type as non-empty interface with 1 heritage", ( ) =>
+	{
+		const ts = convertCoreTypesToTypeScript( wrapDocument( [
+			{
+				name: 'foo',
+				type: 'and',
+				and: [
+					{
+						type: 'object',
+						properties: {
+							f: { required: true, node: { type: 'string' } },
+						},
+						additionalProperties: false,
+					},
+					{
+						type: 'ref',
+						ref: 'bar',
+					},
+				],
+			},
+			{
+				name: 'bar',
+				type: 'object',
+				properties: {
+					b: { required: true, node: { type: 'number' } },
+				},
+				additionalProperties: false,
+			},
+		] ),
+		{ noDescriptiveHeader: true, noDisableLintHeader: true }
+		);
+
+		expect( ts.data ).toMatchSnapshot( );
+	} );
+
+	it( "and-type as non-empty interface with 2 heritage", ( ) =>
+	{
+		const ts = convertCoreTypesToTypeScript( wrapDocument( [
+			{
+				name: 'foo',
+				type: 'and',
+				and: [
+					{
+						type: 'object',
+						properties: {
+							f: { required: true, node: { type: 'string' } },
+						},
+						additionalProperties: false,
+					},
+					{
+						type: 'ref',
+						ref: 'bar',
+					},
+					{
+						type: 'ref',
+						ref: 'baz',
+					},
+				],
+			},
+			{
+				name: 'bar',
+				type: 'object',
+				properties: {
+					b: { required: true, node: { type: 'number' } },
+				},
+				additionalProperties: false,
+			},
+			{
+				name: 'baz',
+				type: 'object',
+				properties: {
+					z: { required: true, node: { type: 'boolean' } },
+				},
+				additionalProperties: false,
+			},
+		] ),
+		{ noDescriptiveHeader: true, noDisableLintHeader: true }
+		);
+
+		expect( ts.data ).toMatchSnapshot( );
+	} );
 } );