[tests] Further revise LSP tests.

org.lflang.tests/src/org/lflang/tests/lsp/ErrorInserter.java

@@ -12,6 +12,7 @@
 import java.util.ListIterator;
 import java.util.Random;
 import java.util.function.BiFunction;
+import java.util.function.BiPredicate;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
@@ -27,8 +28,8 @@ class ErrorInserter {
 
     /** A basic error inserter builder on which more specific error inserters can be built. */
     private static final Builder BASE_ERROR_INSERTER = new Builder()
-        .insertCondition(s -> Stream.of(";", "}", "{").anyMatch(s::endsWith))
-        .insertCondition(s -> !s.trim().startsWith("else"))
+        .insertCondition((s0, s1) -> Stream.of(";", "}", "{").anyMatch(s0::endsWith))
+        .insertCondition((s0, s1) -> !s1.trim().startsWith("else"))
         .insertable("    0 = 1;").insertable("some_undeclared_var1524263 = 9;").insertable("        ++;");
     public static final Builder C = BASE_ERROR_INSERTER
         .replacer("lf_set(", "UNDEFINED_NAME2828376(")
@@ -79,7 +80,7 @@ private boolean get() {
          * @param insertCondition Whether the error inserter is permitted to insert a line after a given line.
          * @throws IOException if the content of {@code originalTest} cannot be read.
          */
-        private AlteredTest(Path originalTest, Predicate<String> insertCondition) throws IOException {
+        private AlteredTest(Path originalTest, BiPredicate<String, String> insertCondition) throws IOException {
             this.badLines = new ArrayList<>();
             this.path = originalTest;
             this.lines = new LinkedList<>();  // Constant-time insertion during iteration is desired.
@@ -88,10 +89,9 @@ private AlteredTest(Path originalTest, Predicate<String> insertCondition) throws
                 boolean ret = true;
                 it.previous();
                 if (it.hasPrevious()) {
-                    ret = insertCondition.test(it.previous());
+                    ret = insertCondition.test(it.previous(), it.next());
                 }
                 it.next();
-                it.next();
                 return ret;
             };
         }
@@ -231,18 +231,18 @@ public T next() {
         }
         private final Node<Function<String, String>> replacers;
         private final Node<String> insertables;
-        private final Predicate<String> insertCondition;
+        private final BiPredicate<String, String> insertCondition;
 
         /** Initializes a builder for error inserters. */
         public Builder() {
-            this(null, null, s -> true);
+            this(null, null, (s0, s1) -> true);
         }
 
         /** Construct a builder with the given replacers and insertables. */
         private Builder(
             Node<Function<String, String>> replacers,
             Node<String> insertables,
-            Predicate<String> insertCondition
+            BiPredicate<String, String> insertCondition
         ) {
             this.replacers = replacers;
             this.insertables = insertables;
@@ -280,9 +280,10 @@ public Builder insertable(String line) {
         }
 
         /**
-         * Record that for any line X, insertCondition(X) is a necessary condition that a line may be inserted after X.
+         * Record that for any lines X, Y, insertCondition(X, Y) is a necessary condition that a line may be inserted
+         * between X and Y.
          */
-        public Builder insertCondition(Predicate<String> insertCondition) {
+        public Builder insertCondition(BiPredicate<String, String> insertCondition) {
             return new Builder(replacers, insertables, insertCondition.and(insertCondition));
         }
 
@@ -302,13 +303,13 @@ public ErrorInserter get(Random random) {
     private final Random random;
     private final ImmutableList<Function<String, String>> replacers;
     private final ImmutableList<String> insertables;
-    private final Predicate<String> insertCondition;
+    private final BiPredicate<String, String> insertCondition;
 
     private ErrorInserter(
         Random random,
         ImmutableList<Function<String, String>> replacers,
         ImmutableList<String> insertables,
-        Predicate<String> insertCondition
+        BiPredicate<String, String> insertCondition
     ) {
         this.random = random;
         this.replacers = replacers;