fix(sniper): Fix rounding error in indentation detection on single ty…

…pe member (INRIA#3722)

src/main/java/spoon/support/sniper/internal/IndentationDetector.java

@@ -79,9 +79,9 @@ private static Pair<Integer, Boolean> guessIndentationStyle(List<String> wsPrece
 			indentationSize = 1;
 		}
 
-		boolean usesTabs = wsPrecedingTypeMembers.stream()
+		boolean usesTabs = (double) wsPrecedingTypeMembers.stream()
 				.filter(s -> s.contains("\t"))
-				.count() >= wsPrecedingTypeMembers.size() / 2;
+				.count() >= (double) wsPrecedingTypeMembers.size() / 2;
 		return Pair.of(indentationSize, usesTabs);
 	}
 

src/test/java/spoon/test/prettyprinter/TestSniperPrinter.java

@@ -420,7 +420,7 @@ public void testAddedImportStatementPlacedOnSeparateLineInFileWithPackageStateme
 	@Test
 	public void testAddedElementsIndentedWithAppropriateIndentationStyle() {
 		// contract: added elements in a source file should be indented with the same style of
-		// indentation as the rest of the file
+		// indentation as in the rest of the file
 
 		Consumer<CtType<?>> addElements = type -> {
 		    Factory fact = type.getFactory();
@@ -446,6 +446,29 @@ public void testAddedElementsIndentedWithAppropriateIndentationStyle() {
 		testSniper("indentation.FourSpaces", addElements, assertFourSpaces);
 	}
 
+	@Test
+	public void testAddedElementsIndentedWithAppropriateIndentationStyleWhenOnlyOneTypeMemberExists() {
+		// contract: added elements in a source file should be indented with the same style of
+		// indentation as the single type member, when there is only one type member.
+
+		Consumer<CtType<?>> addElement = type -> {
+			Factory fact = type.getFactory();
+			fact.createField(type, new HashSet<>(), fact.Type().INTEGER_PRIMITIVE, "z", fact.createLiteral(2));
+		};
+		final String newField = "int z = 2;";
+
+		BiConsumer<CtType<?>, String> assertTabs = (type, result) ->
+				assertThat(result, containsString("\n\t" + newField));
+		BiConsumer<CtType<?>, String> assertTwoSpaces = (type, result) ->
+				assertThat(result, containsString("\n  " + newField));
+		BiConsumer<CtType<?>, String> assertFourSpaces = (type, result) ->
+				assertThat(result, containsString("\n    " + newField));
+
+		testSniper("indentation.singletypemember.Tabs", addElement, assertTabs);
+		testSniper("indentation.singletypemember.TwoSpaces", addElement, assertTwoSpaces);
+		testSniper("indentation.singletypemember.FourSpaces", addElement, assertFourSpaces);
+	}
+
 	@Test
 	public void testDefaultsToSingleTabIndentationWhenThereAreNoTypeMembers() {
 		// contract: if there are no type members in a compilation unit, the sniper printer defaults

src/test/resources/indentation/singletypemember/FourSpaces.java

@@ -0,0 +1,5 @@
+package indentation.singletypemember;
+
+public class FourSpaces {
+    int x;
+}

src/test/resources/indentation/singletypemember/Tabs.java

@@ -0,0 +1,5 @@
+package indentation.singletypemember;
+
+public class Tabs {
+	int x;
+}

src/test/resources/indentation/singletypemember/TwoSpaces.java

@@ -0,0 +1,5 @@
+package indentation.singletypemember;
+
+public class TwoSpaces {
+  int x;
+}