Merge 1732e2c into 4119fbc

graphql_compiler/ast_manipulation.py

@@ -0,0 +1,29 @@
+# Copyright 2019-present Kensho Technologies, LLC.
+from graphql.language.ast import InlineFragment
+
+from .schema import TYPENAME_META_FIELD_NAME
+
+
+def get_ast_field_name(ast):
+    """Return the normalized field name for the given AST node."""
+    replacements = {
+        # We always rewrite the following field names into their proper underlying counterparts.
+        TYPENAME_META_FIELD_NAME: '@class'
+    }
+    base_field_name = ast.name.value
+    normalized_name = replacements.get(base_field_name, base_field_name)
+    return normalized_name
+
+
+def get_ast_field_name_or_none(ast):
+    """Return the field name for the AST node, or None if the AST is an InlineFragment."""
+    if isinstance(ast, InlineFragment):
+        return None
+    return get_ast_field_name(ast)
+
+
+def get_human_friendly_ast_field_name(ast):
+    """Return a human-friendly name for the AST node, suitable for error messages."""
+    if isinstance(ast, InlineFragment):
+        return 'type coercion to {}'.format(ast.type_condition)
+    return get_ast_field_name(ast)

graphql_compiler/compiler/compiler_frontend.py

@@ -69,6 +69,7 @@
 import six
 
 from . import blocks, expressions
+from ..ast_manipulation import get_ast_field_name
 from ..exceptions import GraphQLCompilationError, GraphQLParsingError, GraphQLValidationError
 from ..schema import COUNT_META_FIELD_NAME, DIRECTIVES
 from .context_helpers import (
@@ -85,10 +86,9 @@
 )
 from .filters import process_filter_directive
 from .helpers import (
-    FoldScopeLocation, Location, get_ast_field_name, get_edge_direction_and_name,
-    get_field_type_from_schema, get_uniquely_named_objects_by_name, get_vertex_field_type,
-    invert_dict, is_vertex_field_name, strip_non_null_from_type, validate_output_name,
-    validate_safe_string
+    FoldScopeLocation, Location, get_edge_direction_and_name, get_field_type_from_schema,
+    get_uniquely_named_objects_by_name, get_vertex_field_type, invert_dict, is_vertex_field_name,
+    strip_non_null_from_type, validate_output_name, validate_safe_string
 )
 from .metadata import LocationInfo, QueryMetadataTable, RecurseInfo
 

graphql_compiler/compiler/directive_helpers.py

@@ -4,12 +4,10 @@
 from graphql.language.ast import InlineFragment
 import six
 
+from ..ast_manipulation import get_ast_field_name, get_ast_field_name_or_none
 from ..exceptions import GraphQLCompilationError
 from .filters import is_filter_with_outer_scope_vertex_field_operator
-from .helpers import (
-    FilterOperationInfo, get_ast_field_name, get_ast_field_name_or_none, get_vertex_field_type,
-    is_vertex_field_type
-)
+from .helpers import FilterOperationInfo, get_vertex_field_type, is_vertex_field_type
 
 
 ALLOWED_DUPLICATED_DIRECTIVES = frozenset({'filter'})

graphql_compiler/compiler/helpers.py

@@ -7,12 +7,10 @@
 
 import funcy
 from graphql import GraphQLList, GraphQLNonNull, GraphQLString, is_type
-from graphql.language.ast import InlineFragment
 from graphql.type.definition import GraphQLInterfaceType, GraphQLObjectType, GraphQLUnionType
 import six
 
 from ..exceptions import GraphQLCompilationError
-from ..schema import TYPENAME_META_FIELD_NAME
 
 
 # These are the Java (OrientDB) representations of the ISO-8601 standard date and datetime formats.
@@ -42,24 +40,6 @@ def get_only_element_from_collection(one_element_collection):
     return funcy.first(one_element_collection)
 
 
-def get_ast_field_name(ast):
-    """Return the normalized field name for the given AST node."""
-    replacements = {
-        # We always rewrite the following field names into their proper underlying counterparts.
-        TYPENAME_META_FIELD_NAME: '@class'
-    }
-    base_field_name = ast.name.value
-    normalized_name = replacements.get(base_field_name, base_field_name)
-    return normalized_name
-
-
-def get_ast_field_name_or_none(ast):
-    """Return the field name for the AST node, or None if the AST is an InlineFragment."""
-    if isinstance(ast, InlineFragment):
-        return None
-    return get_ast_field_name(ast)
-
-
 def get_field_type_from_schema(schema_type, field_name):
     """Return the type of the field in the given type, accounting for field name normalization."""
     if field_name == '@class':

graphql_compiler/exceptions.py

@@ -11,6 +11,10 @@ class GraphQLValidationError(GraphQLError):
     """Exception raised when the provided GraphQL does not validate against the provided schema."""
 
 
+class GraphQLInvalidMacroError(GraphQLError):
+    """Exception raised when the provided GraphQL macro fails to adhere to macro requirements."""
+
+
 class GraphQLCompilationError(GraphQLError):
     """Exception raised when the provided GraphQL cannot be compiled.
 

graphql_compiler/macros/macro_edge/validation_helpers.py

@@ -0,0 +1,72 @@
+# Copyright 2019-present Kensho Technologies, LLC.
+from graphql.language.ast import Field, InlineFragment, OperationDefinition
+
+from ...ast_manipulation import get_human_friendly_ast_field_name
+from ...exceptions import GraphQLInvalidMacroError
+
+
+def _yield_ast_nodes_with_directives(ast):
+    """Get the AST objects where directives appear, anywhere in the given AST.
+
+    Args:
+        ast: GraphQL library AST object, such as a Field, InlineFragment, or OperationDefinition
+
+    Returns:
+        Iterable[Tuple[AST object, Directive]], where each tuple describes an AST node together with
+        the directive it contains. If an AST node contains multiple directives, the AST node will be
+        returned as part of multiple tuples, in no particular order.
+    """
+    for directive in ast.directives:
+        yield (ast, directive)
+
+    if isinstance(ast, (Field, InlineFragment, OperationDefinition)):
+        if ast.selection_set is not None:
+            for sub_selection_set in ast.selection_set.selections:
+                # TODO(predrag): When we make the compiler py3-only, use a "yield from" here.
+                for entry in _yield_ast_nodes_with_directives(sub_selection_set):
+                    yield entry
+    else:
+        raise AssertionError(u'Unexpected AST type received: {} {}'.format(type(ast), ast))
+
+
+def get_directives_for_ast(ast):
+    """Return a dict of directive name -> list of (ast, directive) where that directive is used.
+
+    Args:
+        ast: GraphQL library AST object, such as a Field, InlineFragment, or OperationDefinition
+
+    Returns:
+        Dict[str, List[Tuple[AST object, Directive]]], allowing the user to find the instances
+        in this AST object where a directive with a given name appears; for each of those instances,
+        we record and return the AST object where the directive was applied, together with the AST
+        Directive object describing it together with any arguments that might have been supplied.
+    """
+    result = {}
+
+    for ast, directive in _yield_ast_nodes_with_directives(ast):
+        directive_name = directive.name.value
+        result.setdefault(directive_name, []).append((ast, directive))
+
+    return result
+
+
+def get_only_selection_from_ast(ast):
+    """Return the selected sub-ast, ensuring that there is precisely one."""
+    if ast.selection_set is None:
+        ast_name = get_human_friendly_ast_field_name(ast)
+        raise GraphQLInvalidMacroError(u'Expected an AST with exactly one selection, but got one '
+                                       u'with no selections. Error near AST node named: {}'
+                                       .format(ast_name))
+
+    selections = ast.selection_set.selections
+    if len(selections) != 1:
+        ast_name = get_human_friendly_ast_field_name(ast)
+        selection_names = [
+            get_human_friendly_ast_field_name(selection_ast)
+            for selection_ast in selections
+        ]
+        raise GraphQLInvalidMacroError(u'Expected an AST with exactly one selection, but found '
+                                       u'{} selections at AST node named {}: {}'
+                                       .format(len(selection_names), selection_names, ast_name))
+
+    return selections[0]