ignore string concatenations that must be split over multiple lines

Feuermagier · Apr 4, 2024 · edd819b · edd819b
1 parent 114fd18
commit edd819b
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diff --git a/autograder-core/src/main/java/de/firemage/autograder/core/check/api/UseFormatString.java b/autograder-core/src/main/java/de/firemage/autograder/core/check/api/UseFormatString.java
@@ -31,6 +31,16 @@
 public class UseFormatString extends IntegratedCheck {
     private static final int MIN_NUMBER_CONCATENATIONS = 3;
     private static final int MIN_NUMBER_LITERALS = 2;
+    // A line is about 120 - 140 characters long. Assuming a relatively long constant name,
+    // there remain around 70 characters for the string value.
+    //
+    // For longer string values one will split the string into multiple lines:
+    //
+    // "This is a very long string that is split into multiple lines"
+    //     + " to make it more readable."
+    //
+    // Those should not be flagged.
+    private static final int MAXIMUM_STRING_LENGTH_IN_LINE = 55;
 
     private List<CtExpression<?>> getFormatArgs(CtBinaryOperator<?> ctBinaryOperator) {
         List<CtExpression<?>> result = new ArrayList<>();
@@ -107,6 +117,10 @@ private String buildFormattedString(Iterable<? extends CtExpression<?>> ctExpres
             args.add(ctExpression.prettyprint());
         }
 
+        if (args.isEmpty() && formatString.length() >= MAXIMUM_STRING_LENGTH_IN_LINE) {
+            return null;
+        }
+
         if (args.isEmpty() && !hasInlineNewline) {
             return "\"%s\"".formatted(formatString.toString());
         }

diff --git a/autograder-core/src/test/java/de/firemage/autograder/core/check/api/TestUseFormatString.java b/autograder-core/src/test/java/de/firemage/autograder/core/check/api/TestUseFormatString.java
@@ -148,4 +148,23 @@ public String toString() {
 
         problems.assertExhausted();
     }
+
+    @Test
+    void testLongConstant() throws LinterException, IOException {
+        ProblemIterator problems = this.checkIterator(StringSourceInfo.fromSourceString(
+            JavaVersion.JAVA_17,
+            "Field",
+            """
+                public class Field {
+                    private static final String MY_VERY_LONG_CONSTANT_STRING = "This is a very long constant string that is used in the code."
+                        + "It is so long that it has to be split over multiple lines."
+                        + "It is so long that it has to be split over multiple lines."
+                        + "It is so long that it has to be split over multiple lines."
+                        + "It is so long that it has to be split over multiple lines.";
+                }
+                """
+        ), PROBLEM_TYPES);
+
+        problems.assertExhausted();
+    }
 }