fix #478: Format bubble text according to Scratch 2.0

Author: adazem009

src/scratch/target.cpp

@@ -570,8 +570,21 @@ const std::string &Target::bubbleText() const
  */
 void Target::setBubbleText(const std::string &text)
 {
+    // https://github.com/scratchfoundation/scratch-vm/blob/7313ce5199f8a3da7850085d0f7f6a3ca2c89bf6/src/blocks/scratch3_looks.js#L251-L257
+    const Value v(text);
+    std::string converted = text;
+
+    // Non-integers should be rounded to 2 decimal places (no more, no less), unless they're small enough that rounding would display them as 0.00.
+    if (v.isValidNumber()) {
+        const double num = v.toDouble();
+
+        if (std::abs(num) >= 0.01 && (v % 1).toDouble() != 0)
+            converted = Value(std::round(num * 100) / 100).toString();
+    }
+
+    // Limit the length of the string
     size_t limit = 330;
-    impl->bubbleText = text.substr(0, limit);
+    impl->bubbleText = converted.substr(0, limit);
 }
 
 /*! Returns the engine. */

test/scratch_classes/target_test.cpp

@@ -780,6 +780,38 @@ TEST(TargetTest, BubbleText)
     target.setBubbleText(longstr);
     ASSERT_EQ(target.bubbleText().length(), 330);
     ASSERT_EQ(target.bubbleText(), longstr.substr(0, 330));
+
+    // Integers should be left unchanged
+    target.setBubbleText("8");
+    ASSERT_EQ(target.bubbleText(), "8");
+
+    target.setBubbleText("-52");
+    ASSERT_EQ(target.bubbleText(), "-52");
+
+    target.setBubbleText("0");
+    ASSERT_EQ(target.bubbleText(), "0");
+
+    // Non-integers should be rounded to 2 decimal places (no more, no less), unless they're small enough that rounding would display them as 0.00 (#478)
+    target.setBubbleText("8.324");
+    ASSERT_EQ(target.bubbleText(), "8.32");
+
+    target.setBubbleText("-52.576");
+    ASSERT_EQ(target.bubbleText(), "-52.58");
+
+    target.setBubbleText("3.5");
+    ASSERT_EQ(target.bubbleText(), "3.5");
+
+    target.setBubbleText("0.015");
+    ASSERT_EQ(target.bubbleText(), "0.02");
+
+    target.setBubbleText("-0.015");
+    ASSERT_EQ(target.bubbleText(), "-0.02");
+
+    target.setBubbleText("0.005");
+    ASSERT_EQ(target.bubbleText(), "0.005");
+
+    target.setBubbleText("-0.005");
+    ASSERT_EQ(target.bubbleText(), "-0.005");
 }
 
 TEST(TargetTest, Engine)