Use StringJoiner where possible to simplify String joining

Closes gh-23300
2019-07-16 20:45:21 +03:00
parent 5190eaf503
commit 1d6e44ab04
3 changed files with 155 additions and 127 deletions
--- a/spring-core/src/test/java/org/springframework/core/style/DefaultValueStylerTest.java
+++ b/spring-core/src/test/java/org/springframework/core/style/DefaultValueStylerTest.java
@@ -0,0 +1,99 @@
+package org.springframework.core.style;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class DefaultValueStylerTest {
+
+	private DefaultValueStyler styler = new DefaultValueStyler();
+
+	@Test
+	public void style() throws NoSuchMethodException {
+		assertThat(styler.style(null)).isEqualTo("[null]");
+
+		assertThat(styler.style("str")).isEqualTo("'str'");
+
+		assertThat(styler.style(String.class)).isEqualTo("String");
+
+		assertThat(styler.style(String.class.getMethod("toString"))).isEqualTo("toString@String");
+	}
+
+	@Test
+	public void style_plainObject() {
+		final Object obj = new Object();
+
+		assertThat(styler.style(obj)).isEqualTo(String.valueOf(obj));
+	}
+
+	@Test
+	public void style_map() {
+		Map<String, Integer> map = Collections.emptyMap();
+		assertThat(styler.style(map)).isEqualTo("map[[empty]]");
+
+		map = Collections.singletonMap("key", 1);
+		assertThat(styler.style(map)).isEqualTo("map['key' -> 1]");
+
+		map = new HashMap<>();
+		map.put("key1", 1);
+		map.put("key2", 2);
+		assertThat(styler.style(map)).isEqualTo("map['key1' -> 1, 'key2' -> 2]");
+	}
+
+	@Test
+	public void style_entry() {
+		final Map<String, Integer> map = new LinkedHashMap<>();
+		map.put("key1", 1);
+		map.put("key2", 2);
+
+		final Iterator<Map.Entry<String, Integer>> entries = map.entrySet().iterator();
+
+		assertThat(styler.style(entries.next())).isEqualTo("'key1' -> 1");
+		assertThat(styler.style(entries.next())).isEqualTo("'key2' -> 2");
+	}
+
+	@Test
+	public void style_collection() {
+		List<Integer> list = Collections.emptyList();
+		assertThat(styler.style(list)).isEqualTo("list[[empty]]");
+
+		list = Collections.singletonList(1);
+		assertThat(styler.style(list)).isEqualTo("list[1]");
+
+		list = Arrays.asList(1, 2);
+		assertThat(styler.style(list)).isEqualTo("list[1, 2]");
+	}
+
+	@Test
+	public void style_primitiveArray() {
+		int[] array = new int[0];
+		assertThat(styler.style(array)).isEqualTo("array<Object>[[empty]]");
+
+		array = new int[]{1};
+		assertThat(styler.style(array)).isEqualTo("array<Integer>[1]");
+
+		array = new int[]{1, 2};
+		assertThat(styler.style(array)).isEqualTo("array<Integer>[1, 2]");
+	}
+
+	@Test
+	public void style_objectArray() {
+		String[] array = new String[0];
+		assertThat(styler.style(array)).isEqualTo("array<String>[[empty]]");
+
+		array = new String[]{"str1"};
+		assertThat(styler.style(array)).isEqualTo("array<String>['str1']");
+
+		array = new String[]{"str1", "str2"};
+		assertThat(styler.style(array)).isEqualTo("array<String>['str1', 'str2']");
+	}
+
+}