Add strip_ignored_characters utility function

Replicates graphql/graphql-js@081db43

Author: Cito

README.md

@@ -13,7 +13,7 @@ a query language for APIs created by Facebook.
 [![Code Style](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
 
 The current version 1.0.3 of GraphQL-core-next is up-to-date with GraphQL.js version
-14.2.1. All parts of the API are covered by an extensive test suite of currently 1758
+14.2.1. All parts of the API are covered by an extensive test suite of currently 1776
 unit tests.
 
 

docs/modules/pyutils.rst

@@ -9,6 +9,7 @@ PyUtils
 .. autofunction:: dedent
 .. autoclass:: EventEmitter
 .. autoclass:: EventEmitterAsyncIterator
+.. autofunction:: inspect
 .. autofunction:: is_finite
 .. autofunction:: is_integer
 .. autofunction:: is_invalid
@@ -17,3 +18,5 @@ PyUtils
 .. autofunction:: or_list
 .. autofunction:: quoted_or_list
 .. autofunction:: suggestion_list
+.. autofunction:: ReadOnlyError
+.. autofunction:: ReadOnlyList

docs/modules/utilities.rst

@@ -7,11 +7,11 @@ The GraphQL query recommended for a full schema introspection:
 
 .. autofunction:: get_introspection_query
 
-Gets the target Operation from a Document:
+Get the target Operation from a Document:
 
 .. autofunction:: get_operation_ast
 
-Gets the Type for the target Operation AST:
+Get the Type for the target Operation AST:
 
 .. autofunction:: get_operation_root_type
 
@@ -29,7 +29,7 @@ Build a GraphQLSchema from GraphQL Schema language:
 .. autofunction:: build_schema
 .. autofunction:: get_description
 
-Extends an existing GraphQLSchema from a parsed GraphQL Schema language AST:
+Extend an existing GraphQLSchema from a parsed GraphQL Schema language AST:
 
 .. autofunction:: extend_schema
 
@@ -64,30 +64,35 @@ type system:
 
 .. autoclass:: TypeInfo
 
-Coerces a Python value to a GraphQL type, or produces errors:
+Coerce a Python value to a GraphQL type, or produce errors:
 
 .. autofunction:: coerce_value
 
-Concatenates multiple AST together:
+Concatenate multiple ASTs together:
 
 .. autofunction:: concat_ast
 
-Separates an AST into an AST per Operation:
+Separate an AST into an AST per Operation:
 
 .. autofunction:: separate_operations
 
+Strip characters that are not significant to the validity or execution
+of a GraphQL document:
+
+.. autofunction:: strip_ignored_characters
+
 Comparators for types:
 
 .. autofunction:: is_equal_type
 .. autofunction:: is_type_sub_type_of
 .. autofunction:: do_types_overlap
 
-Asserts that a string is a valid GraphQL name:
+Assert that a string is a valid GraphQL name:
 
 .. autofunction:: assert_valid_name
 .. autofunction:: is_valid_name_error
 
-Compares two GraphQLSchemas and detects breaking changes:
+Compare two GraphQLSchemas and detect breaking changes:
 
 .. autofunction:: find_breaking_changes
 .. autofunction:: find_dangerous_changes
@@ -97,6 +102,6 @@ Compares two GraphQLSchemas and detects breaking changes:
 .. autoclass:: DangerousChange
 .. autoclass:: DangerousChangeType
 
-Report all deprecated usage within a GraphQL document:
+Report all deprecated usages within a GraphQL document:
 
 .. autofunction:: find_deprecated_usages

graphql/__init__.py

@@ -313,11 +313,11 @@
     # Produce the GraphQL query recommended for a full schema introspection.
     # Accepts optional IntrospectionOptions.
     get_introspection_query,
-    # Gets the target Operation from a Document
+    # Get the target Operation from a Document.
     get_operation_ast,
-    # Gets the Type for the target Operation AST.
+    # Get the Type for the target Operation AST.
     get_operation_root_type,
-    # Convert a GraphQLSchema to an IntrospectionQuery
+    # Convert a GraphQLSchema to an IntrospectionQuery.
     introspection_from_schema,
     # Build a GraphQLSchema from an introspection result.
     build_client_schema,
@@ -327,7 +327,7 @@
     build_schema,
     # @deprecated: Get the description from a schema AST node.
     get_description,
-    # Extends an existing GraphQLSchema from a parsed GraphQL Schema language AST.
+    # Extend an existing GraphQLSchema from a parsed GraphQL Schema language AST.
     extend_schema,
     # Sort a GraphQLSchema.
     lexicographic_sort_schema,
@@ -348,21 +348,24 @@
     # A helper to use within recursive-descent visitors which need to be aware of the
     # GraphQL type system.
     TypeInfo,
-    # Coerces a Python value to a GraphQL type, or produces errors.
+    # Coerce a Python value to a GraphQL type, or produce errors.
     coerce_value,
-    # Concatenates multiple AST together.
+    # Concatenates multiple ASTs together.
     concat_ast,
-    # Separates an AST into an AST per Operation.
+    # Separate an AST into an AST per Operation.
     separate_operations,
+    # Strip characters that are not significant to the validity or execution
+    # of a GraphQL document.
+    strip_ignored_characters,
     # Comparators for types
     is_equal_type,
     is_type_sub_type_of,
     do_types_overlap,
-    # Asserts a string is a valid GraphQL name.
+    # Assert a string is a valid GraphQL name.
     assert_valid_name,
     # Determine if a string is a valid GraphQL name.
     is_valid_name_error,
-    # Compares two GraphQLSchemas and detects breaking changes.
+    # Compare two GraphQLSchemas and detect breaking changes.
     find_breaking_changes,
     find_dangerous_changes,
     BreakingChange,
@@ -622,6 +625,7 @@
     "coerce_value",
     "concat_ast",
     "separate_operations",
+    "strip_ignored_characters",
     "is_equal_type",
     "is_type_sub_type_of",
     "do_types_overlap",

graphql/utilities/__init__.py

@@ -7,13 +7,13 @@
 # The GraphQL query recommended for a full schema introspection.
 from .introspection_query import get_introspection_query
 
-# Gets the target Operation from a Document
+# Get the target Operation from a Document.
 from .get_operation_ast import get_operation_ast
 
-# Gets the Type for the target Operation AST.
+# Get the Type for the target Operation AST.
 from .get_operation_root_type import get_operation_root_type
 
-# Convert a GraphQLSchema to an IntrospectionQuery
+# Convert a GraphQLSchema to an IntrospectionQuery.
 from .introspection_from_schema import introspection_from_schema
 
 # Build a GraphQLSchema from an introspection result.
@@ -22,7 +22,7 @@
 # Build a GraphQLSchema from GraphQL Schema language.
 from .build_ast_schema import build_ast_schema, build_schema, get_description
 
-# Extends an existing GraphQLSchema from a parsed GraphQL Schema language AST.
+# Extend an existing GraphQLSchema from a parsed GraphQL Schema language AST.
 from .extend_schema import extend_schema
 
 # Sort a GraphQLSchema.
@@ -52,22 +52,26 @@
 # the GraphQL type system
 from .type_info import TypeInfo
 
-# Coerces a Python value to a GraphQL type, or produces errors.
+# Coerce a Python value to a GraphQL type, or produce errors.
 from .coerce_value import coerce_value
 
-# Concatenates multiple AST together.
+# Concatenate multiple ASTs together.
 from .concat_ast import concat_ast
 
-# Separates an AST into an AST per Operation.
+# Separate an AST into an AST per Operation.
 from .separate_operations import separate_operations
 
+# Strip characters that are not significant to the validity or execution
+# of a GraphQL document.
+from .strip_ignored_characters import strip_ignored_characters
+
 # Comparators for types
 from .type_comparators import is_equal_type, is_type_sub_type_of, do_types_overlap
 
-# Asserts that a string is a valid GraphQL name
+# Assert that a string is a valid GraphQL name.
 from .assert_valid_name import assert_valid_name, is_valid_name_error
 
-# Compares two GraphQLSchemas and detects breaking changes.
+# Compare two GraphQLSchemas and detect breaking changes.
 from .find_breaking_changes import (
     BreakingChange,
     BreakingChangeType,
@@ -77,7 +81,7 @@
     find_dangerous_changes,
 )
 
-# Report all deprecated usage within a GraphQL document.
+# Report all deprecated usages within a GraphQL document.
 from .find_deprecated_usages import find_deprecated_usages
 
 __all__ = [
@@ -112,6 +116,7 @@
     "print_type",
     "print_value",
     "separate_operations",
+    "strip_ignored_characters",
     "type_from_ast",
     "value_from_ast",
     "value_from_ast_untyped",

graphql/utilities/strip_ignored_characters.py

@@ -0,0 +1,114 @@
+from typing import Union
+
+from ..language import Lexer, Source, TokenKind
+from ..language.block_string import (
+    dedent_block_string_value,
+    get_block_string_indentation,
+)
+from ..language.lexer import is_punctuator_token
+from ..pyutils import inspect
+
+
+def strip_ignored_characters(source: Union[str, Source]) -> str:
+    """Strip characters that are ignored anyway.
+
+    Strips characters that are not significant to the validity or execution
+    of a GraphQL document:
+      - UnicodeBOM
+      - WhiteSpace
+      - LineTerminator
+      - Comment
+      - Comma
+      - BlockString indentation
+
+    Note: It is required to have a delimiter character between neighboring
+    non-punctuator tokes and this function always uses single space as delimiter.
+
+    It is guaranteed that both input and output documents if parsed would result
+    in the exact same AST except for nodes location.
+
+    Warning: It is guaranteed that this function will always produce stable results.
+    However, it's not guaranteed that it will stay the same between different
+    releases due to bugfixes or changes in the GraphQL specification.
+    """ '''
+
+    Query example::
+
+        query SomeQuery($foo: String!, $bar: String) {
+          someField(foo: $foo, bar: $bar) {
+            a
+            b {
+              c
+              d
+            }
+          }
+        }
+
+    Becomes::
+
+        query SomeQuery($foo:String!$bar:String){someField(foo:$foo bar:$bar){a b{c d}}}
+
+    SDL example:
+
+        """
+        Type description
+        """
+        type Foo {
+          """
+          Field description
+          """
+          bar: String
+        }
+
+     Becomes::
+
+        """Type description""" type Foo{"""Field description""" bar:String}
+    '''
+    source_obj = Source(source) if isinstance(source, str) else source
+    if not isinstance(source_obj, Source):
+        raise TypeError(
+            f"Must provide string or Source. Received: {inspect(source_obj)}"
+        )
+
+    body = source_obj.body
+    lexer = Lexer(source_obj)
+    stripped_body = ""
+    was_last_added_token_non_punctuator = False
+    while lexer.advance().kind != TokenKind.EOF:
+        current_token = lexer.token
+        token_kind = current_token.kind
+
+        # Every two non-punctuator tokens should have space between them.
+        # Also prevent case of non-punctuator token following by spread resulting
+        # in invalid token (e.g.`1...` is invalid Float token).
+        is_non_punctuator = not is_punctuator_token(current_token)
+        if was_last_added_token_non_punctuator:
+            if is_non_punctuator or current_token.kind == TokenKind.SPREAD:
+                stripped_body += " "
+
+        token_body = body[current_token.start : current_token.end]
+        if token_kind == TokenKind.BLOCK_STRING:
+            stripped_body += dedent_block_string(token_body)
+        else:
+            stripped_body += token_body
+
+        was_last_added_token_non_punctuator = is_non_punctuator
+
+    return stripped_body
+
+
+def dedent_block_string(block_str: str) -> str:
+    """Skip leading and trailing triple quotations"""
+    raw_str = block_str[3:-3]
+    body = dedent_block_string_value(raw_str)
+
+    lines = body.splitlines()
+    if get_block_string_indentation(lines) > 0:
+        body = "\n" + body
+
+    last_char = body[-1:]
+    has_trailing_quote = last_char == '"' and body[-4:] != '\\"""'
+    if has_trailing_quote or last_char == "\\":
+        body += "\n"
+
+    return '"""' + body + '"""'