#91 implement MMAC via XML/XSL

src/main/java/org/jpeek/App.java

@@ -114,7 +114,8 @@ public void analyze() throws IOException {
  final XML skeleton = new Skeleton(base).xml();
  this.save(skeleton.toString(), "skeleton.xml");
  final Iterable<Report> reports = new ListOf<>(
- new Report(skeleton, "LCOM", this.params, 10.0d, -5.0d)
+ new Report(skeleton, "LCOM", this.params, 10.0d, -5.0d),
+ new Report(skeleton, "MMAC", this.params, 0.5d, 0.25d)
  );
  new IoCheckedScalar<>(
  new AndInThreads(

src/main/resources/org/jpeek/metrics/MMAC.xsl

@@ -0,0 +1,95 @@
+<?xml version="1.0"?>
+<!--
+The MIT License (MIT)
+
+Copyright (c) 2017 Yegor Bugayenko
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+-->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
+ <xsl:template match="skeleton">
+ <metric>
+ <xsl:apply-templates select="@*"/>
+ <title>MMAC</title>
+ <description>
+ Method-Method through Attributes Cohesion (MMAC).
+ The MMAC is the average cohesion of all pairs of methods.
+ In simple words this metric shows how much methods have the
+ same parameters or return types. When class has some number
+ of methods and most of them operate the same parameters it
+ assumes better. It looks like class contains overloaded
+ methods. Preferably when class has only one method with
+ parameters and/or return type and it assumes that class
+ do only one thing. Value of MMAC metric is better for these
+ one classes.
+ Metric value is in interval [0, 1]. Value closer to 1 is better.
+ </description>
+ <xsl:apply-templates select="node()"/>
+ </metric>
+ </xsl:template>
+ <xsl:template match="class">
+ <xsl:variable name="class" select="."/>
+ <xsl:variable name="methods_count" select="count($class/methods/method[@ctor='false'])"/>
+ <xsl:variable name="types"
+ select="distinct-values($class/methods/method/args/arg[@type!='V']/@type)"/>
+ <xsl:variable name="types_count" select="count($types)"/>
+ <xsl:variable name="type_methods">
+ <xsl:for-each select="$types">
+ <xsl:variable name="type" select="."/>
+ <xsl:variable name="count"
+ select="count($class/methods/method[@ctor='false' and args/arg/@type=$type])"/>
+ <count>
+ <xsl:value-of select="$count * ($count - 1)"/>
+ </count>
+ </xsl:for-each>
+ </xsl:variable>
+ <xsl:copy>
+ <xsl:attribute name="value">
+ <xsl:choose>
+ <xsl:when test="$methods_count = 0 or $types_count = 0">
+ <xsl:text>0</xsl:text>
+ </xsl:when>
+ <xsl:when test="$methods_count = 1">
+ <xsl:text>1</xsl:text>
+ </xsl:when>
+ <xsl:otherwise>
+ <xsl:value-of
+ select="format-number(sum($type_methods/count)
+ div ($methods_count * $types_count * ($methods_count - 1)),
+ '0.####')"/>
+ </xsl:otherwise>
+ </xsl:choose>
+ </xsl:attribute>
+ <xsl:apply-templates select="@*"/>
+ <vars>
+ <var id="methods">
+ <xsl:value-of select="$methods_count"/>
+ </var>
+ <var id="types">
+ <xsl:value-of select="$types_count"/>
+ </var>
+ </vars>
+ </xsl:copy>
+ </xsl:template>
+ <xsl:template match="node()|@*">
+ <xsl:copy>
+ <xsl:apply-templates select="node()|@*"/>
+ </xsl:copy>
+ </xsl:template>
+</xsl:stylesheet>

src/test/java/org/jpeek/MetricsTest.java

@@ -69,7 +69,16 @@ public static Collection<Object[]> targets() {
  new Object[] {"OverloadMethods", "LCOM", 0.0d},
  new Object[] {"TwoCommonAttributes", "LCOM", 3.0d},
  new Object[] {"WithoutAttributes", "LCOM", 0.0d},
- new Object[] {"OneMethodCreatesLambda", "LCOM", 1.0d}
+ new Object[] {"OneMethodCreatesLambda", "LCOM", 1.0d},
+ new Object[] {"Bar", "MMAC", 1.0d},
+ new Object[] {"Foo", "MMAC", 1.0d},
+ new Object[] {"MethodsWithDiffParamTypes", "MMAC", 0.037d},
+ new Object[] {"NoMethods", "MMAC", 0.0d},
+ new Object[] {"OneVoidMethodWithoutParams", "MMAC", 0.0d},
+ new Object[] {"OverloadMethods", "MMAC", 0.7222d},
+ new Object[] {"TwoCommonAttributes", "MMAC", 0.3333d},
+ new Object[] {"WithoutAttributes", "MMAC", 1.0d},
+ new Object[] {"OneMethodCreatesLambda", "MMAC", 0.0d}
  );
  }