DSL Builders

A quick introductions into DSLs/Typesafe builders with Kotlin.
by Gesh Markov
presented on October 26, 2017 at @Magicline

Transcript

1. DSL Builders gesh@yelp.com
2. public final class MockResponse implements Cloneable
3. public final class MockResponse implements Cloneable
4. public class MockResponseBuilder { private final MockResponse response = new MockResponse(); public MockResponseBuilder withAsset(String asset) { response.addHeader("Content-Type", "application/json"); try (InputStream in = InstrumentationRegistry.getContext().getAssets().open(asset)){ response.setBody(new Buffer().readFrom(in)); } return this; }
5. public class MockResponseBuilder { private final MockResponse response = new MockResponse(); public MockResponseBuilder withAsset(String asset) { response.addHeader("Content-Type", "application/json"); try (InputStream in = InstrumentationRegistry.getContext().getAssets().open(asset)){ response.setBody(new Buffer().readFrom(in)); } return this; } new MockResponseBuilder.withAsset(“my-awesome.json”).build()
6. public class MockResponseBuilder { private final MockResponse response = new MockResponse() ; public MockResponseBuilder withAsset(String asset) { response.addHeader( "Content-Type" , "application/json" ); try (InputStream in = InstrumentationRegistry. getContext().getAssets().open(asset)){ response.setBody( new Buffer().readFrom(in)) ; } return this; } new MockResponseBuilder.withAsset(“my-awesome.json”) .setResponseCode(404) .addHeader(“foo”, “bar”).build()
7. fun MockResponse.body(init: Buffer.() -> Unit) { val buffer = Buffer() buffer.init() body = buffer } fun Buffer.readFromTestAsset(responseJsonPath: String) { InstrumentationRegistry.context.assets.open(responseJsonPath).use { readFrom(it) } }
8. fun mockResponse(init: MockResponse.() -> Unit): MockResponse { val response = MockResponse() response.init() return response }
9. fun mockResponse(init: MockResponse.() -> Unit): MockResponse { val response = MockResponse() response.init() return response } mockResponse { body { readFromTestAsset(“my-awesome.json”) } }
10. fun MockResponse.addHeaders(vararg pairs: Pair<String, String>) { pairs.forEach { addHeader(it.first, it.second) } } mockResponse { body { readFromTestAsset(“my-awesome.json”) } statusCode = 404 addHeaders(“foo” to “bar”, “baz” to “qux”) }
11. new MockResponseBuilder.withAsset(“my-awesome.json”).build() .setResponseCode(404) .addHeader(“foo”, “bar”) .addHeader(“baz”, “qux”).build(); mockResponse { body { readFromTestAsset(“my-awesome.json”) } statusCode = 404 addHeaders(“foo” to “bar”, “baz” to “qux”) }