From 92b54d83a3388e80dd8a340aacda0e7e7858041e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20=C5=9Aliwak?= <kamil.sliwak@codepoets.it>
Date: Fri, 14 Feb 2020 19:49:45 +0100
Subject: [PATCH] [yul-phaser] Common: Add geneSubstitution() mutation

---
 test/yulPhaser/Common.cpp     | 12 ++++++++++++
 test/yulPhaser/Common.h       |  5 +++++
 test/yulPhaser/CommonTest.cpp | 11 +++++++++++
 3 files changed, 28 insertions(+)

diff --git a/test/yulPhaser/Common.cpp b/test/yulPhaser/Common.cpp
index 52cde9590..f9000921f 100644
--- a/test/yulPhaser/Common.cpp
+++ b/test/yulPhaser/Common.cpp
@@ -31,6 +31,18 @@ function<Mutation> phaser::test::wholeChromosomeReplacement(Chromosome _newChrom
 	return [_newChromosome = move(_newChromosome)](Chromosome const&) { return _newChromosome; };
 }
 
+function<Mutation> phaser::test::geneSubstitution(size_t _geneIndex, string _geneValue)
+{
+	return [=](Chromosome const& _chromosome)
+	{
+		vector<string> newGenes = _chromosome.optimisationSteps();
+		assert(_geneIndex < newGenes.size());
+		newGenes[_geneIndex] = _geneValue;
+
+		return Chromosome(newGenes);
+	};
+}
+
 vector<size_t> phaser::test::chromosomeLengths(Population const& _population)
 {
 	vector<size_t> lengths;
diff --git a/test/yulPhaser/Common.h b/test/yulPhaser/Common.h
index cbec90f78..a59c7eed1 100644
--- a/test/yulPhaser/Common.h
+++ b/test/yulPhaser/Common.h
@@ -59,6 +59,11 @@ public:
 /// Mutation that always replaces the whole chromosome with the one specified in the parameter.
 std::function<Mutation> wholeChromosomeReplacement(Chromosome _newChromosome);
 
+/// Mutation that always replaces the optimisation step at position @a _geneIndex with @a _geneValue.
+///
+/// The chromosome must be long enough for this position to exist.
+std::function<Mutation> geneSubstitution(size_t _geneIndex, std::string _geneValue);
+
 // CHROMOSOME AND POPULATION HELPERS
 
 /// Returns a vector containing lengths of all chromosomes in the population (in the same order).
diff --git a/test/yulPhaser/CommonTest.cpp b/test/yulPhaser/CommonTest.cpp
index 3456a6640..efc511a80 100644
--- a/test/yulPhaser/CommonTest.cpp
+++ b/test/yulPhaser/CommonTest.cpp
@@ -46,6 +46,17 @@ BOOST_AUTO_TEST_CASE(wholeChromosomeReplacement_should_replace_whole_chromosome_
 	BOOST_TEST(mutation(Chromosome("ccc")) == Chromosome("aaa"));
 }
 
+BOOST_AUTO_TEST_CASE(geneSubstitution_should_change_a_single_gene_at_a_given_index)
+{
+	Chromosome chromosome("aaccff");
+
+	function<Mutation> mutation1 = geneSubstitution(0, chromosome.optimisationSteps()[5]);
+	BOOST_TEST(mutation1(chromosome) == Chromosome("faccff"));
+
+	function<Mutation> mutation2 = geneSubstitution(5, chromosome.optimisationSteps()[0]);
+	BOOST_TEST(mutation2(chromosome) == Chromosome("aaccfa"));
+}
+
 BOOST_AUTO_TEST_CASE(chromosomeLengths_should_return_lengths_of_all_chromosomes_in_a_population)
 {
 	shared_ptr<FitnessMetric> fitnessMetric = make_shared<ChromosomeLengthMetric>();