Change action invoke to allow to set the charset

src/main/java/org/mozilla/zest/core/v1/ZestActionInvoke.java

@@ -5,8 +5,10 @@
 
 import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileReader;
 import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -28,6 +30,15 @@ public class ZestActionInvoke extends ZestAction {
 
 	private List<String[]> parameters = new ArrayList<String[]>();
 
+	/**
+	 * The name of the charset used for read operations (for example, read the script or the output of the invoked program).
+	 * <p>
+	 * Might be {@code null}, in which case it is used the default charset of the JVM.
+	 * 
+	 * @see #getCharsetImpl()
+	 */
+	private String charset;
+
 	/**
 	 * Instantiates a new zest action invoke.
 	 */
@@ -52,10 +63,25 @@ public ZestActionInvoke(int index) {
 	 * @param parameters the parameters for the script or the process.
 	 */
 	public ZestActionInvoke(String script, String variableName, List<String[]> parameters) {
+		this(script, variableName, parameters, null);
+	}
+
+	/**
+	 * Constructs a {@code ZestActionInvoke} with the given data.
+	 *
+	 * @param script the name of the script or process to invoke.
+	 * @param variableName the name of the variable to assign the result of the invocation.
+	 * @param parameters the parameters for the script or the process.
+	 * @param charset the name of the charset used for read operations (for example, read the script or the output of the
+	 *			invoked program).
+	 * @since 0.14
+	 */
+	public ZestActionInvoke(String script, String variableName, List<String[]> parameters, String charset) {
 		super();
 		this.script = script;
 		this.variableName = variableName;
 		this.parameters = parameters;
+		this.charset = charset;
 	}
 
 	@Override
@@ -119,7 +145,7 @@ public String invoke(ZestResponse response, ZestRuntime runtime) throws ZestActi
 				p.waitFor();
 
 				// Capture anything written to stdout/err
-	            BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
+	            BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream(), getCharsetImpl()));
 	            String line = null;
 	            while ((line = br.readLine()) != null) {
 	            	sb.append(line);
@@ -136,15 +162,15 @@ public String invoke(ZestResponse response, ZestRuntime runtime) throws ZestActi
 		// Set the same writer so that output not lost
 		engine.getContext().setWriter(runtime.getScriptEngineFactory().getScriptEngine().getContext().getWriter());
 
-		try (FileReader fr = new FileReader(f)) {
+		try (Reader reader = Files.newBufferedReader(f.toPath(), getCharsetImpl())) {
 			Bindings bindings = engine.createBindings();
 			if (this.parameters != null) {
 				for (String[] kvPair : this.parameters) {
 					bindings.put(kvPair[0], runtime.replaceVariablesInString(kvPair[1], false));
 				}
 			}
 
-			Object result =  engine.eval(fr, bindings);
+			Object result =  engine.eval(reader, bindings);
 			if (result == null) {
 				return null;
 			}
@@ -156,6 +182,13 @@ public String invoke(ZestResponse response, ZestRuntime runtime) throws ZestActi
 		}
 	}
 
+	private Charset getCharsetImpl() {
+		if (charset == null || charset.isEmpty()) {
+			return Charset.defaultCharset();
+		}
+		return Charset.forName(charset);
+	}
+
 	public String getVariableName() {
 		return variableName;
 	}
@@ -180,6 +213,28 @@ public void setParameters(List<String[]> parameters) {
 		this.parameters = parameters;
 	}
 
+	/**
+	 * Gets the name of the charset used for read operations (for example, read the script from the file or the output of the
+	 * invoked program).
+	 *
+	 * @return the name of the charset.
+	 * @since 0.14
+	 */
+	public String getCharset() {
+		return charset;
+	}
+
+	/**
+	 * Sets the name of the charset used for read operations (for example, read the script from the file or the output of the
+	 * invoked program).
+	 *
+	 * @param charset the name of the charset.
+	 * @since 0.14
+	 */
+	public void setCharset(String charset) {
+		this.charset = charset;
+	}
+
 	@Override
 	public ZestActionInvoke deepCopy() {
 		ZestActionInvoke copy = new ZestActionInvoke(this.getIndex());
@@ -190,6 +245,7 @@ public ZestActionInvoke deepCopy() {
 			copy.parameters.add(new String[] {kvPair[0], kvPair[1]});
 		}
 		copy.setEnabled(this.isEnabled());
+		copy.setCharset(getCharset());
 		return copy;
 	}
 

src/test/java/org/mozilla/zest/test/v1/ZestActionInvokeUnitTest.java

@@ -5,6 +5,7 @@
 
 import static org.junit.Assert.assertEquals;
 
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -26,12 +27,14 @@ public void shouldUseArgsPassedInConstructor() throws Exception {
 		String script = "script.js";
 		String variable = "var";
 		List<String[]> parameters = new ArrayList<>();
+		String charset = StandardCharsets.UTF_8.name();
 		// When
-		ZestActionInvoke invokeAction = new ZestActionInvoke(script, variable, parameters);
+		ZestActionInvoke invokeAction = new ZestActionInvoke(script, variable, parameters, charset);
 		// Then
 		assertEquals(invokeAction.getScript(), script);
 		assertEquals(invokeAction.getVariableName(), variable);
 		assertEquals(invokeAction.getParameters(), parameters);
+		assertEquals(invokeAction.getCharset(), charset);
 	}
 
 	/**
@@ -143,6 +146,7 @@ public void shouldReplaceVariablesPassedAsParameters() throws Exception {
 	public void testSerialization() {
 		ZestActionInvoke inv = new ZestActionInvoke();
 		inv.setVariableName("test");
+		inv.setCharset(StandardCharsets.UTF_8.name());
 		inv.setParameters(params(param("first", "AAA"), param("second", "BBB")));
 
 		inv.setScript(ZestActionInvokeUnitTest.class.getResource("/data/simple-script.js").getPath());
@@ -154,6 +158,7 @@ public void testSerialization() {
 		assertEquals(inv.getElementType(), inv2.getElementType());
 		assertEquals(inv.getVariableName(), inv2.getVariableName());
 		assertEquals(inv.getScript(), inv2.getScript());
+		assertEquals(inv.getCharset(), inv2.getCharset());
 		assertEquals(inv.getParameters().size(), inv2.getParameters().size());
 		for (int i=0; i < inv.getParameters().size(); i++) {
 			assertEquals(inv.getParameters().get(i).length, inv2.getParameters().get(i).length);