Fully move add_imports to main sort_imports entry point

1 files changed, 38 insertions, 5 deletions

diff --git a/isort/api.py b/isort/api.py
index 2ce9ead3..00b4c4fd 100644
--- a/isort/api.py
+++ b/isort/api.py
@@ -11,11 +11,12 @@ from .exceptions import (
     IntroducedSyntaxErrors,
     UnableToDetermineEncoding,
 )
-from .format import remove_whitespace, show_unified_diff, format_natural
+from .format import format_natural, remove_whitespace, show_unified_diff
 from .io import File
 from .settings import DEFAULT_CONFIG, FILE_SKIP_COMMENT, Config
 
 IMPORT_START_IDENTIFIERS = ("from ", "from.import", "import ", "import*")
+COMMENT_INDICATORS = ('"""', "'''", "'", '"', "#")
 
 
 def _config(
@@ -142,15 +143,38 @@ def sort_imports(
     - `output_stream`: Text stream to output sorted inputs into.
     - `config`: Config settings to use when sorting imports. Defaults settings.DEFAULT_CONFIG.
     """
-    add_imports = (format_natural(addition) for addition in config.add_imports)
+    line_separator: str = config.line_ending
+    add_imports = [format_natural(addition) for addition in config.add_imports]
     import_section: str = ""
     in_quote: str = ""
     first_comment_index_start: int = -1
     first_comment_index_end: int = -1
     contains_imports: bool = False
     in_top_comment: bool = False
+    first_import_section: bool = True
     section_comments = [f"# {heading}" for heading in config.import_headings.values()]
+
+    def additional_imports() -> str:
+        nonlocal add_imports
+        nonlocal line_separator
+        nonlocal contains_imports
+
+        if not add_imports:
+            return ""
+
+        if not line_separator:
+            line_separator = "\n"
+
+        fomatted_imports: str = line_separator.join(add_imports) + line_separator
+        contains_imports = True
+        add_imports = []
+        return fomatted_imports
+
+    index: int = 0
     for index, line in enumerate(input_stream):
+        if not line_separator:
+            line_separator = line[-1]
+
         if index == 1 and line.startswith("#"):
             in_top_comment = True
         elif in_top_comment:
@@ -208,12 +232,18 @@ def sort_imports(
                 not_imports = True
 
         if not_imports:
+            if not in_top_comment and not in_quote and not import_section and not line.lstrip().startswith(COMMENT_INDICATORS):
+                import_section = additional_imports()
+
             if import_section:
-                import_section += config.line_ending.join(add_imports)
+                import_section += additional_imports()
                 import_section += line
                 if not contains_imports:
                     output_stream.write(import_section)
                 else:
+                    if first_import_section:
+                        import_section = import_section.lstrip(line_separator)
+                        first_import_section = False
                     output_stream.write(
                         output.sorted_imports(
                             parse.file_contents(import_section, config=config), config, extension
@@ -226,13 +256,16 @@ def sort_imports(
                 not_imports = False
 
     if import_section:
+        import_section += additional_imports()
         if not contains_imports:
             output_stream.write(import_section)
         else:
-            import_section += config.line_ending.join(add_imports)
+            if first_import_section:
+                import_section = import_section.lstrip(line_separator)
             output_stream.write(
                 output.sorted_imports(
                     parse.file_contents(import_section, config=config), config, extension
                 )
             )
-    output_stream.write(config.line_ending.join(add_imports))
+    elif index > 1 or config.force_adds:
+        output_stream.write(additional_imports())