Add avoidLineContinuations option to UseTextBlocks (#975)

Add a new recipe option `avoidLineContinuations` (default: false) that,
when enabled, avoids using `\` line continuation escapes in text blocks
where the content contains newlines. Non-newline-joined strings are
placed on the same text block line instead.

Previously with the option enabled, "foo\n" + "bar" + " baz" produces:
    foo
    bar baz

Without the option (default), the existing behavior is preserved:
    foo
    bar\
     baz

Fixes moderneinc/customer-requests#1763

Author: Jenson3210

src/main/java/org/openrewrite/java/migrate/lang/UseTextBlocks.java

@@ -52,12 +52,27 @@ public class UseTextBlocks extends Recipe {
             required = false)
     boolean convertStringsWithoutNewlines;
 
+    @Option(displayName = "Whether to avoid line continuation escape sequences.",
+            description = "When enabled, the recipe avoids using `\\` line continuation escapes in text blocks " +
+                          "where the content contains newlines. Non-newline-joined strings are placed on the same " +
+                          "text block line instead. The default value is false.",
+            example = "true",
+            required = false)
+    boolean avoidLineContinuations;
+
     public UseTextBlocks() {
         convertStringsWithoutNewlines = true;
+        avoidLineContinuations = false;
     }
 
     public UseTextBlocks(boolean convertStringsWithoutNewlines) {
         this.convertStringsWithoutNewlines = convertStringsWithoutNewlines;
+        this.avoidLineContinuations = false;
+    }
+
+    public UseTextBlocks(boolean convertStringsWithoutNewlines, boolean avoidLineContinuations) {
+        this.convertStringsWithoutNewlines = convertStringsWithoutNewlines;
+        this.avoidLineContinuations = avoidLineContinuations;
     }
 
     String displayName = "Use text blocks";
@@ -122,14 +137,15 @@ private J.Literal toTextBlock(J.Binary binary, String content, List<J.Literal> s
                 stringLiterals = stringLiterals.stream()
                         .filter(s -> s.getValue() != null && !s.getValue().toString().isEmpty())
                         .collect(toList());
+                boolean skipLineContinuations = avoidLineContinuations && containsNewLineInContent(content);
                 for (int i = 0; i < stringLiterals.size(); i++) {
                     String s = requireNonNull(stringLiterals.get(i).getValue()).toString();
                     sb.append(s);
                     originalContent.append(s);
                     if (i != stringLiterals.size() - 1) {
                         String nextLine = requireNonNull(stringLiterals.get(i + 1).getValue()).toString();
                         char nextChar = nextLine.charAt(0);
-                        if (!s.endsWith("\n") && nextChar != '\n') {
+                        if (!s.endsWith("\n") && nextChar != '\n' && !skipLineContinuations) {
                             sb.append(passPhrase);
                         }
                     }

src/test/java/org/openrewrite/java/migrate/lang/UseTextBlocksTest.java

@@ -879,6 +879,99 @@ void shouldNotUpdateKotlinCode() {
         );
     }
 
+    @Issue("https://github.com/moderneinc/customer-requests/issues/1763")
+    @Test
+    void noLineContinuationWhenContentHasNewlines() {
+        rewriteRun(
+          spec -> spec.recipe(new UseTextBlocks(true, true)),
+          //language=java
+          java(
+            """
+              class Test {
+                  String query = "select count(1) cls_count\\n" +
+                                 "from my_table\\n" +
+                                 "where a.id = b.id\\n" +
+                                 "and a.ts > b.ts\\n" +
+                                 "and a.id = :tag_id \\n" +
+                                 "and a.stat_cd = 'ACTV'" +
+                                 " and a.del_fl = 'N'" +
+                                 " and a.rgn = :region";
+              }
+              """,
+            """
+              class Test {
+                  String query = \"""
+                                 select count(1) cls_count
+                                 from my_table
+                                 where a.id = b.id
+                                 and a.ts > b.ts
+                                 and a.id = :tag_id\\s
+                                 and a.stat_cd = 'ACTV' and a.del_fl = 'N' and a.rgn = :region\""";
+              }
+              """
+          )
+        );
+    }
+
+    @Issue("https://github.com/moderneinc/customer-requests/issues/1763")
+    @Test
+    void noLineContinuationInMixedConcatenation() {
+        rewriteRun(
+          spec -> spec.recipe(new UseTextBlocks(true, true)),
+          //language=java
+          java(
+            """
+              class Test {
+                  String query = "select b.id, b.val\\n" +
+                                 "from my_table b, other_table c\\n" +
+                                 "where c.no = :no\\n" +
+                                 "and b.vrsn = c.vrsn" +
+                                 " and b.rgn = :region" +
+                                 " and b.del_fl = 'N'" +
+                                 " and c.rgn = :region";
+              }
+              """,
+            """
+              class Test {
+                  String query = \"""
+                                 select b.id, b.val
+                                 from my_table b, other_table c
+                                 where c.no = :no
+                                 and b.vrsn = c.vrsn and b.rgn = :region and b.del_fl = 'N' and c.rgn = :region\""";
+              }
+              """
+          )
+        );
+    }
+
+    @Issue("https://github.com/moderneinc/customer-requests/issues/1763")
+    @Test
+    void noLineContinuationInMiddleOfMixedConcatenation() {
+        rewriteRun(
+          spec -> spec.recipe(new UseTextBlocks(true, true)),
+          //language=java
+          java(
+            """
+              class Test {
+                  String query = "select b.id\\n" +
+                                 "from my_table" +
+                                 " inner join other_table\\n" +
+                                 "where b.id = :id\\n";
+              }
+              """,
+            """
+              class Test {
+                  String query = \"""
+                                 select b.id
+                                 from my_table inner join other_table
+                                 where b.id = :id
+                                 \""";
+              }
+              """
+          )
+        );
+    }
+
     @Issue("https://github.com/openrewrite/rewrite-migrate-java/issues/555")
     @Test
     void textBlockTrailingEscape() {