Rework themes support

- Add theme settings for figures.
- Settings for styles are now in it own class and
  ThemeSettings are wrapping those.
- Prefixed formatting string to have `style-` prefix.
- Templates can now use added `figures` dictionary which
  is resolved per activated theme.
- Create `dump` theme.
- New `ThemeActive` interface where default impl uses dump
  theme if `CI` or `NO_COLOR` env is set.
- Rework existing templates.
- Fixes #442

spring-shell-autoconfigure/src/main/java/org/springframework/shell/boot/SpringShellProperties.java

@@ -174,7 +174,7 @@ public class SpringShellProperties {
 
 	public static class Theme {
 
-		private String name = "default";
+		private String name;
 
 		public String getName() {
 			return name;

spring-shell-autoconfigure/src/main/java/org/springframework/shell/boot/ThemingAutoConfiguration.java

@@ -16,35 +16,57 @@
 package org.springframework.shell.boot;
 
 import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.shell.style.TemplateExecutor;
 import org.springframework.shell.style.Theme;
+import org.springframework.shell.style.ThemeActive;
 import org.springframework.shell.style.ThemeRegistry;
 import org.springframework.shell.style.ThemeResolver;
 import org.springframework.shell.style.ThemeSettings;
+import org.springframework.util.StringUtils;
 
 @Configuration(proxyBeanMethods = false)
 @EnableConfigurationProperties(SpringShellProperties.class)
 public class ThemingAutoConfiguration {
 
+	@Bean
+	@ConditionalOnMissingBean
+	public ThemeActive themeActive() {
+		return () -> {
+			if (System.getenv("CI") != null || System.getenv("NO_COLOR") != null) {
+				return "dump";
+			}
+			return "default";
+		};
+	}
+
 	@Bean
 	public ThemeRegistry themeRegistry(ObjectProvider<Theme> themes) {
 		ThemeRegistry registry = new ThemeRegistry();
-		registry.register(Theme.of("default", ThemeSettings.themeSettings()));
+		registry.register(Theme.of("default", ThemeSettings.defaults()));
+		registry.register(Theme.of("dump", ThemeSettings.dump()));
 		themes.orderedStream().forEachOrdered(registry::register);
 		return registry;
 	}
 
 	@Bean
-	public ThemeResolver shellThemeResolver(ThemeRegistry themeRegistry, SpringShellProperties properties) {
-		return new ThemeResolver(themeRegistry, properties.getTheme().getName());
+	public ThemeResolver shellThemeResolver(ThemeRegistry themeRegistry, SpringShellProperties properties,
+			ThemeActive themeActive) {
+		String themeName = properties.getTheme().getName();
+		if (!StringUtils.hasText(themeName)) {
+			themeName = themeActive.get();
+		}
+		if (!StringUtils.hasText(themeName)) {
+			themeName = "default";
+		}
+		return new ThemeResolver(themeRegistry, themeName);
 	}
 
 	@Bean
 	public TemplateExecutor templateExecutor(ThemeResolver themeResolver) {
 		return new TemplateExecutor(themeResolver);
 	}
-
 }

spring-shell-autoconfigure/src/test/java/org/springframework/shell/boot/SpringShellPropertiesTests.java

@@ -40,7 +40,7 @@ public class SpringShellPropertiesTests {
 					assertThat(properties.getScript().isEnabled()).isTrue();
 					assertThat(properties.getInteractive().isEnabled()).isTrue();
 					assertThat(properties.getNoninteractive().isEnabled()).isTrue();
-					assertThat(properties.getTheme().getName()).isEqualTo("default");
+					assertThat(properties.getTheme().getName()).isNull();
 					assertThat(properties.getCommand().getClear().isEnabled()).isTrue();
 					assertThat(properties.getCommand().getHelp().isEnabled()).isTrue();
 					assertThat(properties.getCommand().getHelp().getGroupingMode()).isEqualTo(GroupingMode.GROUP);

spring-shell-autoconfigure/src/test/java/org/springframework/shell/boot/ThemingAutoConfigurationTests.java

@@ -15,17 +15,24 @@
  */
 package org.springframework.shell.boot;
 
+import java.util.stream.Stream;
+
+import org.assertj.core.api.AbstractAssert;
+import org.assertj.core.api.InstanceOfAssertFactory;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.shell.style.FigureSettings;
+import org.springframework.shell.style.StyleSettings;
 import org.springframework.shell.style.TemplateExecutor;
 import org.springframework.shell.style.Theme;
 import org.springframework.shell.style.ThemeRegistry;
 import org.springframework.shell.style.ThemeResolver;
 import org.springframework.shell.style.ThemeSettings;
+import org.springframework.util.StringUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -35,19 +42,22 @@ public class ThemingAutoConfigurationTests {
 			.withConfiguration(AutoConfigurations.of(ThemingAutoConfiguration.class));
 
 	@Test
-	public void testDefaults() {
+	void createsDefaultBeans() {
 		this.contextRunner
 				.run(context -> {
 					assertThat(context).hasSingleBean(TemplateExecutor.class);
 					assertThat(context).hasSingleBean(ThemeRegistry.class);
 					ThemeRegistry registry = context.getBean(ThemeRegistry.class);
 					assertThat(registry.get("default")).isNotNull();
+					assertThat(registry.get("dump")).isNotNull();
 					assertThat(context).hasSingleBean(ThemeResolver.class);
+					ThemeResolver resolver = context.getBean(ThemeResolver.class);
+					assertThat(resolver).extracting("theme").asInstanceOf(THEME).hasName("default", "dump");
 				});
 	}
 
 	@Test
-	public void testRegistersCustomTheme() {
+	public void canRegisterCustomTheme() {
 		this.contextRunner
 				.withUserConfiguration(CustomThemeConfig.class)
 				.run(context -> {
@@ -79,5 +89,36 @@ public class ThemingAutoConfigurationTests {
 	}
 
 	static class MyThemeSettings extends ThemeSettings {
+		MyThemeSettings() {
+			super(StyleSettings.defaults(), FigureSettings.defaults());
+		}
 	}
+
+	InstanceOfAssertFactory<Theme, ThemeAssert> THEME = new InstanceOfAssertFactory<>(Theme.class,
+			ThemeAssertions::assertThat);
+
+	static class ThemeAssertions {
+
+		public static ThemeAssert assertThat(Theme actual) {
+			return new ThemeAssert(actual);
+		}
+	}
+
+	static class ThemeAssert extends AbstractAssert<ThemeAssert, Theme> {
+
+		public ThemeAssert(Theme actual) {
+			super(actual, ThemeAssert.class);
+		}
+
+		public ThemeAssert hasName(String... names) {
+			isNotNull();
+			boolean match = Stream.of(names).filter(n -> actual.getName().equals(n)).findFirst().isPresent();
+			if (!match) {
+				failWithMessage("Expected theme to have names %s but was %s",
+						StringUtils.arrayToCommaDelimitedString(names), actual.getName());
+			}
+			return this;
+		}
+	}
+
 }