Also filter out empty text segments

peps/pep-0501.rst

@@ -328,6 +328,12 @@ following behaviour:
             text._raw = raw
             return text
 
+        @staticmethod
+        def merge(text_segments:Sequence[TemplateLiteralText]) -> TemplateLiteralText:
+            if len(text_segments) == 1:
+                return text_segments[0]
+            return TemplateLiteralText("".join(t._raw for t in text_segments))
+
         @property
         def raw(self) -> str:
             return self._raw
@@ -349,10 +355,6 @@ following behaviour:
             return TemplateLiteralText(self._raw * factor)
         __rmul__ = __mul__
 
-        @staticmethod
-        def merge(text_segments:Sequence[TemplateLiteralText]) -> TemplateLiteralText:
-            return TemplateLiteralText("".join(t._raw for t in text_segments))
-
     class TemplateLiteralField(NamedTuple):
         # This is mostly a renamed version of the InterpolationConcrete type in PEP 750
         # However:
@@ -391,11 +393,12 @@ following behaviour:
             self = super().__new__(cls)
             self._raw_template = raw_template
             # Check if there are any adjacent text segments that need merging
+            # or any empty text segments that need discarding
             text_expected = True
             needs_merge = False
             for segment in segments:
                 if isinstance(segment, TemplateLiteralText):
-                    if not text_expected:
+                    if not text_expected or not segment:
                         needs_merge = True
                         break
                     text_expected = False
@@ -404,13 +407,14 @@ following behaviour:
             if not needs_merge:
                 self._segments = segments
                 return self
-            # Ensure any consecutive runs of text fields are merged together
+            # Merge consecutive runs of text fields and drop any empty text fields
             merged_segments:list[TemplateLiteralText|TemplateLiteralField] = []
             pending_merge:list[TemplateLiteralText] = []
             for segment in segments:
                 match segment:
                     case TemplateLiteralText() as text_segment:
-                        pending_merge.append(text_segment)
+                        if text_segment:
+                            pending_merge.append(text_segment)
                     case TemplateLiteralField():
                         if pending_merge:
                             merged_segments.append(TemplateLiteralText.merge(pending_merge))