Make handling of whitespace in reflowed lines consistent

cushon · cushon · commit d0e770720f21 · 2019-04-03T14:18:49.000-07:00
We always want it at the beginning of lines, not at the end.  This fixes
an interaction with the logic for preserving existing line breaks at
non-whitespace boundaries.

MOE_MIGRATED_REVID=241641348
diff --git a/core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java b/core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java
@@ -161,36 +161,40 @@ public Void visitLiteral(LiteralTree literalTree, Void aVoid) {
   private static ImmutableList<String> stringComponents(
       String input, JCTree.JCCompilationUnit unit, List<Tree> flat) {
     ImmutableList.Builder<String> result = ImmutableList.builder();
+    StringBuilder piece = new StringBuilder();
     for (Tree tree : flat) {
       // adjust for leading and trailing double quotes
       String text = input.substring(getStartPosition(tree) + 1, getEndPosition(unit, tree) - 1);
       int start = 0;
       for (int idx = 0; idx < text.length(); idx++) {
         if (CharMatcher.whitespace().matches(text.charAt(idx))) {
-          result.add(text.substring(start, idx));
-          start = idx;
-          continue;
-        }
-        if (hasEscapedWhitespaceAt(text, idx) != -1) {
-          result.add(text.substring(start, idx));
-          start = idx;
-          continue;
-        }
-
-        if (hasEscapedNewlineAt(text, idx) != -1) {
+          // continue below
+        } else if (hasEscapedWhitespaceAt(text, idx) != -1) {
+          // continue below
+        } else if (hasEscapedNewlineAt(text, idx) != -1) {
           int length;
           while ((length = hasEscapedNewlineAt(text, idx)) != -1) {
             idx += length;
           }
-          result.add(text.substring(start, idx));
-          start = idx;
+        } else {
           continue;
         }
+        piece.append(text, start, idx);
+        result.add(piece.toString());
+        piece = new StringBuilder();
+        start = idx;
+      }
+      if (piece.length() > 0) {
+        result.add(piece.toString());
+        piece = new StringBuilder();
       }
       if (start < text.length()) {
-        result.add(text.substring(start));
+        piece.append(text, start, text.length());
       }
     }
+    if (piece.length() > 0) {
+      result.add(piece.toString());
+    }
     return result.build();
   }
 
diff --git a/core/src/test/java/com/google/googlejavaformat/java/StringWrapperIntegrationTest.java b/core/src/test/java/com/google/googlejavaformat/java/StringWrapperIntegrationTest.java
@@ -139,13 +139,16 @@ public static Collection<Object[]> parameters() {
       {
         {
           "class T {", //
-          "  String s = \"onelongincrediblyunbrokensentencemovingfromtopictotopicsothatnoonehadachanceto interrupt\";",
+          "  String s ="
+              + " \"onelongincrediblyunbrokensentencemovingfromtopictotopicsothatnoonehadachanceto"
+              + " interrupt\";",
           "}"
         },
         {
           "class T {",
           "  String s =",
-          "      \"onelongincrediblyunbrokensentencemovingfromtopictotopicsothatnoonehadachanceto\"",
+          "     "
+              + " \"onelongincrediblyunbrokensentencemovingfromtopictotopicsothatnoonehadachanceto\"",
           "          + \" interrupt\";",
           "}",
         }
@@ -272,7 +275,8 @@ public static Collection<Object[]> parameters() {
         {
           "class T {",
           "  String s =",
-          "      \"__ onelongincrediblyunbrokensentencemovingfromtopictotopicsothatnoonehadachanceto\"",
+          "      \"__"
+              + " onelongincrediblyunbrokensentencemovingfromtopictotopicsothatnoonehadachanceto\"",
           "          + \" interrupt\";",
           "}",
         }
@@ -306,6 +310,44 @@ public static Collection<Object[]> parameters() {
           "}",
         }
       },
+      {
+        {
+          "class T {", //
+          "  String s =",
+          "      \"aaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbb ccccccccccccccccccccccccccc"
+              + " dddddddddddddddddd\";",
+          "}"
+        },
+        {
+          "class T {",
+          "  String s =",
+          "      \"aaaaaaaaaaaaaaaaaaaaaaaa\"",
+          "          + \" bbbbbbbbbbbbbbbbbb\"",
+          "          + \" ccccccccccccccccccccccccccc\"",
+          "          + \" dddddddddddddddddd\";",
+          "}",
+        }
+      },
+      {
+        {
+          "class T {", //
+          "  String s =",
+          "      \"aaaaaaaaaaaaaaaaaaaaaaaa \"",
+          "          + \"bbbbbbbbbbbbbbbbbb \"",
+          "          + \"ccccccccccccccccccccccccccc \"",
+          "          + \"dddddddddddddddddd\";",
+          "}"
+        },
+        {
+          "class T {",
+          "  String s =",
+          "      \"aaaaaaaaaaaaaaaaaaaaaaaa\"",
+          "          + \" bbbbbbbbbbbbbbbbbb\"",
+          "          + \" ccccccccccccccccccccccccccc\"",
+          "          + \" dddddddddddddddddd\";",
+          "}",
+        }
+      },
     };
     return Arrays.stream(inputsAndOutputs)
         .map(
