From 0961ff2949cd10d4da1e6c7abea7c0fdea7e4d52 Mon Sep 17 00:00:00 2001
From: Antonin Delpeuch <antonin@delpeuch.eu>
Date: Fri, 23 Mar 2018 11:17:38 +0000
Subject: [PATCH] Refuse empty strings in Wikidata schema

---
 .../wikidata/schema/WbStringConstant.java     | 15 +++++++++++
 .../wikidata/schema/WbStringConstantTest.java | 27 +++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 extensions/wikidata/tests/src/org/openrefine/wikidata/schema/WbStringConstantTest.java

diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java
index 5fe0afa0d..7a1ddf9e3 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java
@@ -37,6 +37,8 @@ public class WbStringConstant implements WbExpression<StringValue> {
     @JsonCreator
     public WbStringConstant(@JsonProperty("value") String value) {
         Validate.notNull(value);
+        Validate.isTrue(!value.isEmpty()); // for now we don't accept empty strings
+        // because in the variable counterpart of this expression, they are skipped
         this.value = value;
     }
 
@@ -49,4 +51,17 @@ public class WbStringConstant implements WbExpression<StringValue> {
     public String getValue() {
         return value;
     }
+    
+    @Override
+    public boolean equals(Object other) {
+        if(other == null || !WbStringConstant.class.isInstance(other)) {
+            return false;
+        }
+        return value.equals(((WbStringConstant)other).getValue());
+    }
+    
+    @Override
+    public int hashCode() {
+        return value.hashCode();
+    }
 }
diff --git a/extensions/wikidata/tests/src/org/openrefine/wikidata/schema/WbStringConstantTest.java b/extensions/wikidata/tests/src/org/openrefine/wikidata/schema/WbStringConstantTest.java
new file mode 100644
index 000000000..9066b6c93
--- /dev/null
+++ b/extensions/wikidata/tests/src/org/openrefine/wikidata/schema/WbStringConstantTest.java
@@ -0,0 +1,27 @@
+package org.openrefine.wikidata.schema;
+
+import org.openrefine.wikidata.testing.JacksonSerializationTest;
+import org.testng.annotations.Test;
+import org.wikidata.wdtk.datamodel.helpers.Datamodel;
+import org.wikidata.wdtk.datamodel.interfaces.StringValue;
+
+public class WbStringConstantTest extends WbExpressionTest<StringValue> {
+    
+    private WbStringConstant constant = new WbStringConstant("hello world");
+    
+    @Test
+    public void testSerialize() {
+        JacksonSerializationTest.canonicalSerialization(WbExpression.class, constant,
+                "{\"type\":\"wbstringconstant\",\"value\":\"hello world\"}");
+    }
+    
+    @Test
+    public void testEvaluate() {
+        evaluatesTo(Datamodel.makeStringValue("hello world"), constant);
+    }
+    
+    @Test(expectedExceptions = IllegalArgumentException.class)
+    public void testEmpty() {
+        new WbStringConstant("");
+    }
+}