UriTemplate Implementation Test Cases

Adding unit and integration test cases for the initial set of
UriTemplate expressions and the Uri Template itself.

feignx-core/src/main/java/feign/template/Expression.java

@@ -1,55 +1,92 @@
 package feign.template;
 
 import feign.support.Assert;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
 
 /**
- * Chunk that represents an Expression that, adheres to RFC 6570, and will be resolved
- * during expansion.
+ * Chunk that represents an Expression that, adheres to RFC 6570, and will be resolved during
+ * expansion.
  */
 public abstract class Expression implements Chunk {
 
-  private final String variable;
+  private static final String MULTIPLE_VALUE_DELIMITER = ",";
+  private final Set<String> variables = new LinkedHashSet<>();
   private int limit;
 
   /**
    * Creates a new Expression.
    *
-   * @param variable template.
+   * @param variableSpecification template.
    */
-  protected Expression(String variable) {
-    Assert.isNotEmpty(variable, "variable is required.");
-    this.variable = variable;
+  Expression(String variableSpecification) {
+    Assert.isNotEmpty(variableSpecification, "variable is required.");
+
+    /* remove the leading and trailing braces if necessary */
+    if (variableSpecification.startsWith("{")) {
+      variableSpecification = variableSpecification
+          .substring(1, variableSpecification.length() - 1);
+    }
+
+    if (variableSpecification.contains(MULTIPLE_VALUE_DELIMITER)) {
+      /* multiple variables are present in the spec */
+      String[] variableSpecifications = variableSpecification.split(MULTIPLE_VALUE_DELIMITER);
+      this.variables.addAll(Arrays.asList(variableSpecifications));
+    } else {
+      this.variables.add(variableSpecification);
+    }
     this.limit = -1;
   }
 
   /**
-   * Creates a new Expression, with a prefix limiting the amount of characters to include
-   * during expansion.
+   * Creates a new Expression, with a prefix limiting the amount of characters to include during
+   * expansion.
    *
-   * @param variable template.
-   * @param limit regular variable.
+   * @param variables template.
+   * @param limit regular variables.
    */
-  protected Expression(String variable, int limit) {
-    this(variable);
+  Expression(String variables, int limit) {
+    this(variables);
     this.limit = limit;
   }
 
   /**
-   * Expand this variable based on the value provided.
+   * Expand this variables based on the value provided.
    *
-   * @param value to expand.
+   * @param variables to expand.
    * @return the expanded Expression value.
    */
-  public String expand(Object value) {
-    String result = this.expandInternal(value);
+  String expand(Map<String, ?> variables) {
+    StringBuilder expanded = new StringBuilder();
+    for (String variable : this.variables) {
+      if (variables.containsKey(variable)) {
+        String result = this.expandInternal(variables.get(variable));
+        if (result != null) {
+
+          /* trim the result to the limit if present */
+          if (this.limit > 0) {
+            result = result.substring(0, limit);
+          }
 
-    /* honor the limit, if present */
-    return (this.limit > 0) ? result.substring(0, limit) : result;
+          /* append the list delimiter based on this expression type when appending additional
+           * values  */
+          if (expanded.length() != 0) {
+            expanded.append(",");
+          }
+          expanded.append(result);
+        }
+      }
+    }
+    return expanded.toString();
   }
 
   /**
-   * Expand this variable based on the value provided.
+   * Expand this variables based on the value provided.
    *
    * @param value to expand.
    * @return the expanded Expression value.
@@ -59,10 +96,10 @@ public String expand(Object value) {
   /**
    * Variable name for this expression.
    *
-   * @return expression variable.
+   * @return expression variables.
    */
-  public String getVariable() {
-    return this.variable;
+  public Collection<String> getVariables() {
+    return Collections.unmodifiableSet(this.variables);
   }
 
   /**
@@ -77,9 +114,9 @@ public int getLimit() {
   @Override
   public String getValue() {
     if (this.limit > 0) {
-      return "{" + this.variable + ":" + this.limit + "}";
+      return "{" + this.variables + ":" + this.limit + "}";
     }
-    return "{" + this.variable + "}";
+    return "{" + this.variables + "}";
   }
 
   @Override
@@ -91,16 +128,16 @@ public boolean equals(Object obj) {
       return false;
     }
     Expression that = (Expression) obj;
-    return variable.equals(that.variable);
+    return variables.equals(that.variables);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(variable);
+    return Objects.hash(variables);
   }
 
   @Override
   public String toString() {
-    return "Expression [" + "variable='" + variable + "'" + ", limit=" + limit + "]";
+    return "Expression [" + "variables='" + variables + "'" + ", limit=" + limit + "]";
   }
 }

feignx-core/src/main/java/feign/template/Expressions.java

@@ -35,7 +35,7 @@ public static Expression create(String variableSpec) {
               + "variable: " + variableName + ".  Limit provided is not a valid integer.");
         }
       }
-      return new SimpleExpression(variableName);
+      return new SimpleExpression(variableName, limit);
     } else {
       throw new IllegalArgumentException("Supplied variable specification is not valid.  Please "
           + "see RFC 6570 for more information how to construct a variable specification");

feignx-core/src/main/java/feign/template/SimpleExpression.java

@@ -1,27 +1,31 @@
 package feign.template;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 
 public class SimpleExpression extends Expression {
 
   protected SimpleExpression(String variable) {
     super(variable);
   }
 
+  public SimpleExpression(String variable, int limit) {
+    super(variable, limit);
+  }
+
   @Override
   protected String expandInternal(Object value) {
-    /* collections of values are expanded differently */
     if (Iterable.class.isAssignableFrom(value.getClass())) {
       List<String> values = new ArrayList<>();
       for (Object item : (Iterable) value) {
         values.add(item.toString());
       }
       return this.expandIterable(values);
+    } else {
+      return value.toString();
     }
-
-    /* return the value, as a string */
-    return value.toString();
   }
 
   /**
@@ -33,4 +37,10 @@ protected String expandInternal(Object value) {
   protected String expandIterable(List<String> values) {
     return String.join(",", values);
   }
+
+  private String expandValue(Object value) {
+    StringBuilder expanded = new StringBuilder();
+
+    return expanded.toString();
+  }
 }

feignx-core/src/main/java/feign/template/UriTemplate.java

@@ -3,6 +3,7 @@
 import feign.support.StringUtils;
 import java.net.URI;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
@@ -65,12 +66,8 @@ public URI expand(Map<String, ?> variables) {
    * @return the expanded value or {@literal null} if the expression variable is undefined.
    */
   private String expand(Expression expression, Map<String, ?> variables) {
-    /* look for the expression value in the variable map */
-    String name = expression.getVariable();
-    if (variables.containsKey(name)) {
-      return expression.expand(variables.get(name));
-    }
-    return null;
+    /* delegate to the expression */
+    return expression.expand(variables);
   }
 
   /**

feignx-core/src/test/java/feign/template/SimpleExpressionTest.java

@@ -0,0 +1,87 @@
+package feign.template;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+
+class SimpleExpressionTest {
+
+  @Test
+  void expand_withSingleVariable() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one}");
+    assertThat(simpleExpression.getVariables()).hasSize(1);
+    assertThat(simpleExpression.getLimit()).isEqualTo(-1);
+
+    String result = simpleExpression.expand(Collections.singletonMap("one", "two"));
+    assertThat(result).isEqualTo("two");
+  }
+
+  @Test
+  void expand_withMultipleVariables() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one,two,three}");
+    assertThat(simpleExpression.getVariables()).hasSize(3);
+    assertThat(simpleExpression.getLimit()).isEqualTo(-1);
+
+    Map<String, Object> variables = new LinkedHashMap<>();
+    variables.put("one", "first");
+    variables.put("two", "second");
+    variables.put("three", "third");
+    String result = simpleExpression.expand(variables);
+    assertThat(result).isEqualTo("first,second,third");
+  }
+
+  @Test
+  void expand_undefinedAreRemoved() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one,two,three}");
+
+    Map<String, Object> variables = new LinkedHashMap<>();
+    variables.put("one", "first");
+    variables.put("two", "second");
+    String result = simpleExpression.expand(variables);
+    assertThat(result).isEqualTo("first,second");
+  }
+
+  @Test
+  void expand_emptyAreKept() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one,two,three}");
+
+    Map<String, Object> variables = new LinkedHashMap<>();
+    variables.put("one", "first");
+    variables.put("two", "second");
+    variables.put("three", "");
+    String result = simpleExpression.expand(variables);
+    assertThat(result).isEqualTo("first,second,");
+  }
+
+  @Test
+  void expand_withLimit() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one}", 5);
+    assertThat(simpleExpression.getVariables()).hasSize(1);
+    assertThat(simpleExpression.getLimit()).isEqualTo(5);
+
+    String result = simpleExpression.expand(Collections.singletonMap("one", "limited"));
+    assertThat(result).isEqualTo("limit");
+  }
+
+  @Test
+  void expand_withIterable() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one}");
+
+    String result = simpleExpression.expand(
+        Collections.singletonMap("one", Arrays.asList("first", "second", "third")));
+    assertThat(result).isEqualTo("first,second,third");
+  }
+
+  @Test
+  void expand_withPctEncoding() {
+    SimpleExpression simpleExpression = new SimpleExpression("{one}");
+
+    String result = simpleExpression.expand(
+        Collections.singletonMap("one", "Hello World"));
+    assertThat(result).isEqualTo("Hello%20World");
+  }
+}

mvnw.cmd

@@ -62,7 +62,7 @@ if not "%JAVA_HOME%" == "" goto OkJHome
 
 echo.
 echo Error: JAVA_HOME not found in your environment. >&2
-echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo Please set the JAVA_HOME variables in your environment to match the >&2
 echo location of your Java installation. >&2
 echo.
 goto error
@@ -73,7 +73,7 @@ if exist "%JAVA_HOME%\bin\java.exe" goto init
 echo.
 echo Error: JAVA_HOME is set to an invalid directory. >&2
 echo JAVA_HOME = "%JAVA_HOME%" >&2
-echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo Please set the JAVA_HOME variables in your environment to match the >&2
 echo location of your Java installation. >&2
 echo.
 goto error