Add smoke test

.gitignore

@@ -7,3 +7,6 @@ build
 .settings/
 .project
 .classpath
+
+tests/**/*/analysis.json
+tests/**/*/tags.json

tests/hamming/.meta/config.json

@@ -0,0 +1,49 @@
+{
+  "authors": [
+    "wdjunaidi"
+  ],
+  "contributors": [
+    "c-thornton",
+    "ChristianWilkie",
+    "FridaTveit",
+    "javaeeeee",
+    "jmrunkle",
+    "jonnynabors",
+    "jtigger",
+    "kytrinyx",
+    "lemoncurry",
+    "matthewmorgan",
+    "michael-berger-FR",
+    "michaelspets",
+    "mirkoperillo",
+    "msomji",
+    "muzimuzhi",
+    "odzeno",
+    "sjwarner-bp",
+    "SleeplessByte",
+    "Smarticles101",
+    "sshine",
+    "stkent",
+    "t0dd",
+    "Valkryst",
+    "vasouv",
+    "Zaldrick"
+  ],
+  "files": {
+    "solution": [
+      "src/main/java/Hamming.java"
+    ],
+    "test": [
+      "src/test/java/HammingTest.java"
+    ],
+    "example": [
+      ".meta/src/reference/java/Hamming.java"
+    ],
+    "invalidator": [
+      "build.gradle"
+    ]
+  },
+  "blurb": "Calculate the Hamming difference between two DNA strands.",
+  "source": "The Calculating Point Mutations problem at Rosalind",
+  "source_url": "https://rosalind.info/problems/hamm/"
+}

tests/hamming/.meta/src/reference/java/Hamming.java

@@ -0,0 +1,26 @@
+import java.util.function.IntPredicate;
+import java.util.stream.IntStream;
+
+class Hamming {
+    private final int hammingDistance;
+
+    Hamming(String leftStrand, String rightStrand) {
+        String exceptionMessage = "leftStrand and rightStrand must be of equal length.";
+        if (leftStrand.length() != rightStrand.length()) {
+            if (leftStrand.isEmpty()) {
+                exceptionMessage = "left strand must not be empty.";
+            }
+            if (rightStrand.isEmpty()) {
+                exceptionMessage = "right strand must not be empty.";
+            }
+            throw new IllegalArgumentException(exceptionMessage);
+        }
+
+        IntPredicate areNotEqual = index -> leftStrand.charAt(index) != rightStrand.charAt(index);
+        hammingDistance = (int) IntStream.range(0, leftStrand.length()).filter(areNotEqual).count();
+    }
+
+    int getHammingDistance() {
+        return hammingDistance;
+    }
+}

tests/hamming/.meta/tests.toml

@@ -0,0 +1,30 @@
+# This is an auto-generated file. Regular comments will be removed when this
+# file is regenerated. Regenerating will not touch any manually added keys,
+# so comments can be added in a "comment" key.
+
+[f6dcb64f-03b0-4b60-81b1-3c9dbf47e887]
+description = "empty strands"
+
+[54681314-eee2-439a-9db0-b0636c656156]
+description = "single letter identical strands"
+
+[294479a3-a4c8-478f-8d63-6209815a827b]
+description = "single letter different strands"
+
+[9aed5f34-5693-4344-9b31-40c692fb5592]
+description = "long identical strands"
+
+[cd2273a5-c576-46c8-a52b-dee251c3e6e5]
+description = "long different strands"
+
+[919f8ef0-b767-4d1b-8516-6379d07fcb28]
+description = "disallow first strand longer"
+
+[8a2d4ed0-ead5-4fdd-924d-27c4cf56e60e]
+description = "disallow second strand longer"
+
+[5dce058b-28d4-4ca7-aa64-adfe4e17784c]
+description = "disallow left empty strand"
+
+[38826d4b-16fb-4639-ac3e-ba027dec8b5f]
+description = "disallow right empty strand"

tests/hamming/.meta/version

@@ -0,0 +1 @@
+2.3.0

tests/hamming/expected_analysis.json

@@ -0,0 +1 @@
+{"comments":["java.hamming.calculate_distance_in_constructor","java.hamming.should_use_string_is_empty"]}

tests/hamming/expected_tags.json

@@ -0,0 +1 @@
+{}

tests/hamming/src/main/java/Hamming.java

@@ -0,0 +1,53 @@
+class Hamming {
+
+    private String leftStrand;
+    private String rightStrand;
+
+    Hamming(String leftStrand, String rightStrand) {
+
+        validate(leftStrand, rightStrand);
+        this.leftStrand = leftStrand;
+        this.rightStrand = rightStrand;
+    }
+
+
+    private void validate(String leftStrand, String rightStrand) {
+    	validateNotNull(leftStrand, rightStrand);
+    	validateNotOneEmpty(leftStrand, rightStrand);
+    	validateSameLength(leftStrand, rightStrand);
+    }
+
+	private void validateNotNull(String leftStrand, String rightStrand) {
+		if (leftStrand == null || rightStrand == null) {
+			throw new IllegalArgumentException("Either left or right stand is null");
+		}
+	}
+
+	private void validateNotOneEmpty(String leftStrand, String rightStrand) {
+		if (leftStrand.length() == 0 && rightStrand.length() > 0) {
+			throw new IllegalArgumentException("left strand must not be empty.");
+		} else if (rightStrand.length() == 0 && leftStrand.length() > 0) {
+			throw new IllegalArgumentException("right strand must not be empty.");
+		}
+	}
+
+	private void validateSameLength(String leftStrand, String rightStrand) {
+		if (leftStrand.length() != rightStrand.length()) {
+			throw new IllegalArgumentException("leftStrand and rightStrand must be of equal length.");
+		}
+	}
+
+    int getHammingDistance() {
+
+        int strandLen = this.leftStrand.length();
+    	int diffCount = 0;
+    	for (int i = 0; i < strandLen; i++) {
+    		if (this.leftStrand.charAt(i) != this.rightStrand.charAt(i)) {
+    			diffCount++;
+    		}
+    	}
+
+    	return diffCount;
+    }
+
+}