Add partial text contains with resource to TextAssert

Closes gh-1431

initializr-generator-test/src/main/java/io/spring/initializr/generator/test/io/AbstractTextAssert.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
+import java.util.function.Consumer;
 
 import org.assertj.core.api.AbstractStringAssert;
 import org.assertj.core.api.ListAssert;
@@ -52,15 +53,30 @@ public abstract class AbstractTextAssert<SELF extends AbstractStringAssert<SELF>
 	 * @see #isEqualToIgnoringNewLines(CharSequence)
 	 */
 	public SELF hasSameContentAs(Resource expected) {
-		if (!expected.isReadable()) {
-			failWithMessage("Expected resource does not exist: " + expected);
+		return doWithResource(expected, this::isEqualToIgnoringNewLines);
+	}
+
+	/**
+	 * Assert this text contains the content defined by the specified {@link Resource}.
+	 * Differences in newlines are ignored
+	 * @param content a resource with the partial expected content
+	 * @return {@code this} assertion object
+	 * @see #containsIgnoringNewLines(CharSequence...)
+	 */
+	public SELF contains(Resource content) {
+		return doWithResource(content, this::containsIgnoringNewLines);
+	}
+
+	private SELF doWithResource(Resource resource, Consumer<String> resourceAssertions) {
+		if (!resource.isReadable()) {
+			failWithMessage("Resource does not exist: " + resource);
 		}
-		try (InputStream in = expected.getInputStream()) {
+		try (InputStream in = resource.getInputStream()) {
 			String expectedContent = StreamUtils.copyToString(in, StandardCharsets.UTF_8);
-			isEqualToIgnoringNewLines(expectedContent);
+			resourceAssertions.accept(expectedContent);
 		}
 		catch (IOException ex) {
-			failWithMessage("Cannot read expected content " + expected);
+			failWithMessage("Cannot read content " + resource);
 		}
 		return this.myself;
 	}

initializr-generator-test/src/test/java/io/spring/initializr/generator/test/io/TextAssertTests.java

@@ -58,7 +58,7 @@ class TextAssertTests {
 		given(resource.getInputStream()).willThrow(new IOException("Test exception"));
 		assertThatExceptionOfType(AssertionError.class)
 			.isThrownBy(() -> assertThat(forContent("Hello")).hasSameContentAs(resource))
-			.withMessageContaining("Cannot read expected content");
+			.withMessageContaining("Cannot read content");
 	}
 
 	@Test
@@ -106,6 +106,49 @@ class TextAssertTests {
 			.withMessageContaining(file.toString());
 	}
 
+	@Test
+	void containsWithNonReadableResource() {
+		Resource resource = mock(Resource.class);
+		given(resource.isReadable()).willReturn(false);
+		given(resource.toString()).willReturn("project/does-not-exist");
+		assertThatExceptionOfType(AssertionError.class)
+			.isThrownBy(() -> assertThat(forContent("Hello")).contains(resource))
+			.withMessageContaining("project/does-not-exist");
+	}
+
+	@Test
+	void containsWithNonReliableResource() throws IOException {
+		Resource resource = mock(Resource.class);
+		given(resource.isReadable()).willReturn(true);
+		given(resource.getInputStream()).willThrow(new IOException("Test exception"));
+		assertThatExceptionOfType(AssertionError.class)
+			.isThrownBy(() -> assertThat(forContent("Hello")).contains(resource))
+			.withMessageContaining("Cannot read content");
+	}
+
+	@Test
+	void containsWithMatchingResource() throws IOException {
+		assertThat(forContent("Hello World")).contains(createResource("Hello"));
+	}
+
+	@Test
+	void containsMatchingResourceAndDifferentNewLinesInTarget() throws IOException {
+		assertThat(forContent("Hello\nWorld!")).contains(createResource("Hello\r\nWorld"));
+	}
+
+	@Test
+	void containsWithMatchingResourceAndDifferentNewLinesInSource() throws IOException {
+		assertThat(forContent("Hello\r\nWorld!")).contains(createResource("Hello\nWorld"));
+	}
+
+	@Test
+	void containsWithNonMatchingResource() {
+		assertThatExceptionOfType(AssertionError.class)
+			.isThrownBy(() -> assertThat(forContent("Test")).contains(createResource("Hello")))
+			.withMessageContaining("Test")
+			.withMessageContaining("Hello");
+	}
+
 	private AssertProvider<TextAssert> forContent(String content) {
 		return () -> new TextAssert(content);
 	}