Fix yarn execution with Maven proxy defined

frontend-plugin-core/src/main/java/com/github/eirslett/maven/plugins/frontend/lib/ArgumentsParser.java

@@ -71,15 +71,15 @@ List<String> parse(String args) {
         return new ArrayList<>(arguments);
     }
 
-    private static void addArgument(StringBuilder argumentBuilder, List<String> arguments) {
+    static void addArgument(StringBuilder argumentBuilder, List<String> arguments) {
         if (argumentBuilder.length() > 0) {
             String argument = argumentBuilder.toString();
             addArgument(argument, arguments);
             argumentBuilder.setLength(0);
         }
     }
 
-    private static void addArgument(String argument, List<String> arguments) {
+    static void addArgument(String argument, List<String> arguments) {
         if (!arguments.contains(argument)) {
             arguments.add(argument);
         }

frontend-plugin-core/src/main/java/com/github/eirslett/maven/plugins/frontend/lib/YarnArgumentParser.java

@@ -0,0 +1,74 @@
+package com.github.eirslett.maven.plugins.frontend.lib;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+class YarnArgumentsParser {
+
+  private final List<String> additionalArguments;
+
+  YarnArgumentsParser() {
+    this(Collections.<String>emptyList());
+  }
+
+  YarnArgumentsParser(List<String> additionalArguments) {
+    this.additionalArguments = additionalArguments;
+  }
+
+  /**
+   * Parses a given string of arguments, splitting it by characters that are whitespaces according to {@link Character#isWhitespace(char)}.
+   * <p>
+   * This method respects quoted arguments. Meaning that whitespaces appearing phrases that are enclosed by an opening
+   * single or double quote and a closing single or double quote or the end of the string will not be considered.
+   * <p>
+   * All characters excluding whitespaces considered for splitting stay in place.
+   * <p>
+   * Examples:
+   * "foo bar" will be split to ["foo", "bar"]
+   * "foo \"bar foobar\"" will be split to ["foo", "\"bar foobar\""]
+   * "foo 'bar" will be split to ["foo", "'bar"]
+   *
+   * @param args a string of arguments
+   * @return an mutable copy of the list of all arguments
+   */
+  List<String> parse(String args) {
+    if (args == null || "null".equals(args) || args.isEmpty()) {
+      return Collections.emptyList();
+    }
+
+    final List<String> arguments = new LinkedList<>();
+
+    for (String argument : this.additionalArguments) {
+      ArgumentsParser.addArgument(argument, arguments);
+    }
+
+    final StringBuilder argumentBuilder = new StringBuilder();
+    Character quote = null;
+
+    for (int i = 0, l = args.length(); i < l; i++) {
+      char c = args.charAt(i);
+
+      if (Character.isWhitespace(c) && quote == null) {
+        ArgumentsParser.addArgument(argumentBuilder, arguments);
+        continue;
+      } else if (c == '"' || c == '\'') {
+        // explicit boxing allows us to use object caching of the Character class
+        Character currentQuote = Character.valueOf(c);
+        if (quote == null) {
+          quote = currentQuote;
+        } else if (quote.equals(currentQuote)){
+          quote = null;
+        } // else
+        // we ignore the case when a quoted argument contains the other kind of quote
+      }
+
+      argumentBuilder.append(c);
+    }
+
+    ArgumentsParser.addArgument(argumentBuilder, arguments);
+
+    return new ArrayList<>(arguments);
+  }
+}

frontend-plugin-core/src/main/java/com/github/eirslett/maven/plugins/frontend/lib/YarnTaskExecutor.java

@@ -20,7 +20,7 @@ abstract class YarnTaskExecutor {
 
     private final String taskName;
 
-    private final ArgumentsParser argumentsParser;
+    private final YarnArgumentsParser argumentsParser;
 
     private final YarnExecutorConfig config;
 
@@ -42,7 +42,7 @@ public YarnTaskExecutor(YarnExecutorConfig config, String taskName, String taskL
         logger = LoggerFactory.getLogger(getClass());
         this.config = config;
         this.taskName = taskName;
-        this.argumentsParser = new ArgumentsParser(additionalArguments);
+        this.argumentsParser = new YarnArgumentsParser(additionalArguments);
     }
 
     private static String getTaskNameFromLocation(String taskLocation) {