fix: sniper of local variables (#3412)

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

@@ -720,13 +720,14 @@ private void forEachConstantFragment(int start, int end, Consumer<SourceFragment
 		StringBuilder buff = new StringBuilder();
 		CharType lastType = null;
 		int off = start;
+		// basic tokenization based on spaces
 		while (off < end) {
 			char c = sourceCode.charAt(off);
 			CharType type = CharType.fromChar(c);
 			if (type != lastType) {
 				if (lastType != null) {
 					onCharSequence(lastType, buff, consumer);
-					buff.setLength(0);
+					buff.setLength(0); // reset
 				}
 				lastType = type;
 			}
@@ -766,8 +767,10 @@ private void onCharSequence(CharType type, StringBuilder buff, Consumer<SourceFr
 					longestMatcher = strMatcher.getLonger(longestMatcher);
 				}
 			}
+			// nothing has matched, best effort token
 			if (longestMatcher == null) {
-				throw new SpoonException("Unexpected source text: " + buff.toString());
+				consumer.accept(new TokenSourceFragment(str.toString(), TokenType.CODE_SNIPPET));
+				return;
 			}
 			consumer.accept(new TokenSourceFragment(longestMatcher.toString(), longestMatcher.getType()));
 			off += longestMatcher.getLength();

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

@@ -107,6 +107,43 @@ public void testPrintReplacementOfInvocation() {
 		});
 	}
 
+	@Test
+	public void testPrintLocalVariableDeclaration() {
+		// contract: joint local declarations can be sniper-printed in whole unmodified method
+		testSniper(OneLineMultipleVariableDeclaration.class.getName(), type -> {
+			type.getFields().stream().forEach(x -> {x.delete();});
+		}, (type, printed) -> {
+			assertEquals("package spoon.test.prettyprinter.testclasses;\n" +
+					"\n" +
+					"public class OneLineMultipleVariableDeclaration {\n" +
+					"\n" +
+					"\tvoid foo(int a) {\n" +
+					"\t\tint b = 0, e = 1;\n" +
+					"\t\ta = a;\n" +
+					"\t}\n" +
+					"}", printed);
+		});
+	}
+
+	@Test
+	public void testPrintLocalVariableDeclaration2() {
+		// contract: joint local declarations can be sniper-printed
+		testSniper(OneLineMultipleVariableDeclaration.class.getName(), type -> {
+			type.getElements(new TypeFilter<>(CtLocalVariable.class)).get(0).delete();
+		}, (type, printed) -> {
+			assertEquals("package spoon.test.prettyprinter.testclasses;\n" +
+					"\n" +
+					"public class OneLineMultipleVariableDeclaration {int a;\n" +
+					"\n" +
+					"\tint c;\n" +
+					"\n" +
+					"\tvoid foo(int a) {int e = 1;\n" +
+					"\t\ta = a;\n" +
+					"\t}\n" +
+					"}", printed);
+		});
+	}
+
 	@Test
 	public void testPrintOneLineMultipleVariableDeclaration() {
 		// contract: files with joint field declarations can be recompiled after sniper

src/test/java/spoon/test/prettyprinter/testclasses/OneLineMultipleVariableDeclaration.java

@@ -5,6 +5,7 @@ public class OneLineMultipleVariableDeclaration {
 	int a, c;
 
 	void foo(int a) {
+		int b = 0, e = 1;
 		a = a;
 	}
 }