Adding more comments and tests

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/ast/TextBlock.java

@@ -104,7 +104,8 @@ public static char[] formatTextBlock(char[][] lines, int indent, boolean follows
 			// And remove all trailing whitespace
 			// Finally append the \n at the end of the line (except the last line)
 			int trail = length;
-			// Only the last line is really prefixed to the expression
+			// Only the last line is really prefixed to the embedded
+			// expression in a string template
 			if (!precedesExp || i < (size -1)) {
 				for(;trail > 0;) {
 					if (!ScannerHelper.isWhitespace(l[trail-1])) {

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Parser.java

@@ -10046,14 +10046,17 @@ private void consumeTemplate(int token) {
 	int oldStart = this.scanner.startPosition;
 	// What we get from the scanner for text block content will
 	// not contain the text for the embedded expression. This ensures
-	// that the whitespace from those expressions don't meddle with the
+	// that the whitespace from those expressions don't mess with the
 	// formatting of the outer text block.
+	// First get the common indentation for the entire text block
 	int indent = 0;
 	boolean isMultiline = token == TerminalTokens.TokenNameTextBlockTemplate;
 	if (isMultiline) {
 		char[][] lines = this.scanner.getCurrentTextBlockAsLines();
 		indent = TextBlock.getTextBlockIndent(lines);
 	}
+	// Process the text fragments one by one with the common indentation
+	// to get the right formatting for each of them.
 	int start, end;
 	int[] positions = this.scanner.fragPositions;
 	int pointer = 0;

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/StringTemplateTest.java

@@ -721,7 +721,7 @@ public void test027() {
 			options.put(CompilerOptions.OPTION_ReportUnusedLocal, old1);
 		}
 	}
-	public void test028() {
+	public void test027a() {
 		Map<String,String> options = getCompilerOptions(false);
 		String old1 = options.get(CompilerOptions.OPTION_ReportUnusedLocal);
 		options.put(CompilerOptions.OPTION_ReportUnusedLocal, CompilerOptions.ERROR);
@@ -751,6 +751,94 @@ public void test028() {
 			options.put(CompilerOptions.OPTION_ReportUnusedLocal, old1);
 		}
 	}
+	public void test028() {
+		Map<String,String> options = getCompilerOptions(false);
+		String old1 = options.get(CompilerOptions.OPTION_ReportUnusedPrivateMember);
+		options.put(CompilerOptions.OPTION_ReportUnusedPrivateMember, CompilerOptions.ERROR);
+		try {
+			runNegativeTest(
+					new String[] {
+							"X.java",
+							"public class X {\n"
+							+ "  private String abc = \"abc\"; // unused\n"
+							+ "  private String def = \"def\"; // unused\n"
+							+ "  public void main(String[] args) {\n"
+							+ "    String s = STR.\"A simple String \\{def}\";\n"
+							+ "    System.out.println(s);\n"
+							+ "  }\n"
+							+ "}"
+					},
+					"----------\n" +
+					"1. ERROR in X.java (at line 2)\n" +
+					"	private String abc = \"abc\"; // unused\n" +
+					"	               ^^^\n" +
+					"The value of the field X.abc is not used\n" +
+					"----------\n",
+					null,
+					false,
+					options);
+		} finally {
+			options.put(CompilerOptions.OPTION_ReportUnusedPrivateMember, old1);
+		}
+	}
+	public void test028a() {
+		Map<String,String> options = getCompilerOptions(false);
+		String old1 = options.get(CompilerOptions.OPTION_ReportUnusedPrivateMember);
+		options.put(CompilerOptions.OPTION_ReportUnusedPrivateMember, CompilerOptions.ERROR);
+		try {
+			runNegativeTest(
+					new String[] {
+							"X.java",
+							"public class X {\n"
+							+ "  private String abc = \"abc\"; // unused\n"
+							+ "  private String def = \"def\"; // unused\n"
+							+ "  public void main(String[] args) {\n"
+							+ "    String s = STR.\"A simple String \\{clone(def)}\";\n"
+							+ "    System.out.println(s);\n"
+							+ "  }\n"
+							+ "  public String clone(String s) {\n"
+							+ "    return s;\n"
+							+ "  }\n"
+							+ "}"
+					},
+					"----------\n" +
+					"1. ERROR in X.java (at line 2)\n" +
+					"	private String abc = \"abc\"; // unused\n" +
+					"	               ^^^\n" +
+					"The value of the field X.abc is not used\n" +
+					"----------\n",
+					null,
+					false,
+					options);
+		} finally {
+			options.put(CompilerOptions.OPTION_ReportUnusedPrivateMember, old1);
+		}
+	}
+	public void test028b() {
+		Map<String,String> options = getCompilerOptions(false);
+		String old1 = options.get(CompilerOptions.OPTION_ReportUnusedPrivateMember);
+		options.put(CompilerOptions.OPTION_ReportUnusedPrivateMember, CompilerOptions.ERROR);
+		try {
+			runConformTest(
+					new String[] {
+							"X.java",
+							"public class X {\n"
+							+ "  private String abc = \"abc\"; // unused\n"
+							+ "  public void main(String[] args) {\n"
+							+ "    String s = STR.\"A simple String \\{clone(abc)}\";\n"
+							+ "    System.out.println(s);\n"
+							+ "  }\n"
+							+ "  public String clone(String s) {\n"
+							+ "    return \"clone\";\n"
+							+ "  }\n"
+							+ "}"
+					},
+					"A simple String clone",
+					options);
+		} finally {
+			options.put(CompilerOptions.OPTION_ReportUnusedPrivateMember, old1);
+		}
+	}
 	public void test029() {
 		runConformTest(
 				new String[] {
@@ -1129,4 +1217,33 @@ public static void main(String[] args)  {
 				"true",
 				getCompilerOptions());
 	}
+	// 3 levels of nested test blocks with string templates and a method invocation
+	public void test044() {
+		runConformTest(
+				new String[] {
+						"X.java",
+						"""
+public class X {
+    public static void main(String argv[]) {
+String s = STR.\"""
+  \\{
+  STR.\"""
+\\{
+    clone(\"""
+        abcdefg
+        \""")
+}\"""
+
+  }\""";
+      System.out.println(s.equals("clone"));
+    }
+    public static String clone(String s) {
+        return "clone"; //$NON-NLS-1$
+    }
+}
+"""
+				},
+				"true",
+				getCompilerOptions());
+	}
 }