TST: Added test case

for spaces at the beggining of concatneted strings
pandas-dev · ShaharNaveh · Jan 5, 2020 · Jan 5, 2020 · Jan 6, 2020 · Jan 5, 2020
commit ac568e695d3b7c5d9725473f8f8bdf67771f902a
diff --git a/ci/code_checks.sh b/ci/code_checks.sh
@@ -108,6 +108,14 @@ if [[ -z "$CHECK" || "$CHECK" == "lint" ]]; then
     fi
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
+    MSG='Check for wrong space in a string' ; echo $MSG
+    if [[ "$GITHUB_ACTIONS" == "true" ]]; then
+        $BASE_DIR/scripts/validate_spaces_over_concatned_strings.py --format="[error]{source_path}:{line_number}:{msg}" .
+    else
+        $BASE_DIR/scripts/validate_spaces_over_concatned_strings.py .
+    fi
+    RET=$(($RET + $?)) ; echo $MSG "DONE"
+
     echo "isort --version-number"
     isort --version-number
 

diff --git a/scripts/validate_spaces_over_concatned_strings.py b/scripts/validate_spaces_over_concatned_strings.py
@@ -0,0 +1,140 @@
+#!/usr/bin/env python
+"""
+Test case for leading spaces in concated strings.
+
+For example:
+
+# Good
+foo = (
+        "bar "
+        "baz"
+)
+
+
+# Bad
+foo = (
+        "bar"
+        " baz"
+)
+"""
+
+import argparse
+import os
+import sys
+import token
+import tokenize
+from typing import Generator, List, Tuple
+
+FILE_EXTENSIONS_TO_CHECK = (".py", ".pyx", ".pyx.ini", ".pxd")
+
+MSG = "String have a space at the beggining instead, at the end of the previos string."
+
+
+def main(source_path: str, output_format: str) -> bool:
+    """
+    Main entry point of the script.
+
+    Parameters
+    ----------
+    source_path : str
+        Source path representing path to a file/directory.
+    output_format : str
+        Output format of the script.
+
+    Returns
+    -------
+    bool
+        True if found any strings that have a leading space in the wrong line.
+
+    Raises
+    ------
+    ValueError
+        If the `source_path` is not pointing to existing file/directory.
+    """
+    if not os.path.exists(source_path):
+        raise ValueError(
+            "Please enter a valid path, pointing to a valid file/directory."
+        )
+
+    is_failed: bool = False
+
+    if os.path.isfile(source_path):
+        for source_path, line_number in strings_with_wrong_space(source_path):
+            is_failed = True
+            print(
+                output_format.format(
+                    source_path=source_path, line_number=line_number, msg=MSG
+                )
+            )
+
+    for subdir, _, files in os.walk(source_path):
+        for file_name in files:
+            if any(
+                file_name.endswith(extension) for extension in FILE_EXTENSIONS_TO_CHECK
+            ):
+                for source_path, line_number in strings_with_wrong_space(
+                    os.path.join(subdir, file_name)
+                ):
+                    is_failed = True
+                    print(
+                        output_format.format(
+                            source_path=source_path, line_number=line_number, msg=MSG
+                        )
+                    )
+    return is_failed
+
+
+def strings_with_wrong_space(
+    source_path: str,
+) -> Generator[Tuple[str, int], None, None]:
+    """
+    Yielding the file path and the line number of the string to fix.
+
+    Parameters
+    ----------
+    source_path : str
+        File path pointing to a single file.
+
+    Yields
+    ------
+    source_path : str
+        Source file path.
+    line_number : int
+        Line number of the wrong placed space.
+    """
+    with open(source_path, "r") as file_name:
+        tokens: List = list(tokenize.generate_tokens(file_name.readline))
+
+    for first_token, second_token, third_token in zip(tokens, tokens[1:], tokens[2:]):
+        if (
+            first_token[0] == third_token[0] == token.STRING
+            and second_token[0] == token.NL
+        ):
+            # Means we are in a block of concated string
+
+            # Striping the quotes
+            first_string = first_token[1][1:-1]
+            second_string = third_token[1][1:-1]
+
+            if (not first_string.endswith(" ")) and (second_string.startswith(" ")):
+                yield source_path, third_token[2][0]
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Validate spaces over concated strings"
+    )
+
+    parser.add_argument(
+        "path", nargs="?", default=".", help="Source path of file/directory to check."
+    )
+    parser.add_argument(
+        "--format",
+        "-f",
+        default="{source_path}:{line_number}:{msg}",
+        help="Output format of the error message.",
+    )
+
+    args = parser.parse_args()
+
+    sys.exit(main(source_path=args.path, output_format=args.format))