[libgraphql-core-v1] Task 16.6e: Hygiene, from_str family, Schema::resolve_span

crates/libgraphql-core-v1/src/error_note.rs

@@ -10,9 +10,9 @@ use crate::span::Span;
 ///   defined, or where a conflicting field exists)
 ///
 /// This is the schema-layer analogue of
-/// [`libgraphql_parser::GraphQLErrorNote`](libgraphql_parser::GraphQLErrorNote)
+/// [`libgraphql_parser::GraphQLErrorNote`]
 /// in the parser crate. The key difference is that spans here
-/// are [`libgraphql_core::Span`]s (deferred byte-offset + source map ID) rather
+/// are [`Span`]s (deferred byte-offset + source map ID) rather
 /// than pre-resolved `SourceSpan`s, since schema errors may
 /// reference locations across multiple source files loaded at
 /// different times.

crates/libgraphql-core-v1/src/schema/schema_builder.rs

@@ -52,6 +52,8 @@ use indexmap::IndexMap;
 use libgraphql_parser::ast;
 use libgraphql_parser::ByteSpan;
 use libgraphql_parser::GraphQLErrorNoteKind;
+use std::path::Path;
+use std::path::PathBuf;
 
 /// Accumulates GraphQL type definitions, directive definitions,
 /// and schema metadata, then validates and produces an immutable
@@ -409,9 +411,113 @@ impl SchemaBuilder {
     /// errors are collected into the returned `Err` variant
     /// with their original parser spans translated to our
     /// [`Span`] type.
+    ///
+    /// The registered source map carries no source label; when
+    /// loading multiple sources, prefer
+    /// [`load_str_with_label()`](Self::load_str_with_label) so
+    /// diagnostics can identify which source a location refers
+    /// to.
     pub fn load_str(
         &mut self,
         source: &str,
+    ) -> Result<&mut Self, Vec<SchemaBuildError>> {
+        self.load_str_impl(source, /* label = */ None)
+    }
+
+    /// Like [`load_str()`](Self::load_str), but labels the
+    /// registered [`SchemaSourceMap`] with `label` (typically
+    /// the path the source text was read from).
+    ///
+    /// The label is stored as the source map's
+    /// [`file_path()`](SchemaSourceMap::file_path) and is
+    /// surfaced by diagnostics that resolve spans from this
+    /// source, which is especially useful when a schema is
+    /// assembled from multiple source strings.
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// # use libgraphql_core_v1 as libgraphql_core;
+    /// use libgraphql_core::schema::SchemaBuilder;
+    /// use std::path::Path;
+    ///
+    /// let mut builder = SchemaBuilder::new();
+    /// builder.load_str_with_label(
+    ///     "type Query { hello: String }",
+    ///     "schemas/main.graphql",
+    /// ).unwrap();
+    /// let schema = builder.build().unwrap();
+    ///
+    /// assert_eq!(
+    ///     schema.source_maps()[1].file_path(),
+    ///     Some(Path::new("schemas/main.graphql")),
+    /// );
+    /// ```
+    pub fn load_str_with_label(
+        &mut self,
+        source: &str,
+        label: impl AsRef<Path>,
+    ) -> Result<&mut Self, Vec<SchemaBuildError>> {
+        self.load_str_impl(source, Some(label.as_ref().to_path_buf()))
+    }
+
+    /// Convenience: creates a new `SchemaBuilder` and loads
+    /// `source` into it in one step.
+    ///
+    /// Equivalent to [`SchemaBuilder::new()`](Self::new)
+    /// followed by [`load_str()`](Self::load_str). Additional
+    /// sources can still be loaded into the returned builder
+    /// before calling [`build()`](Self::build).
+    ///
+    /// The error type mirrors `load_str`'s
+    /// (`Vec<SchemaBuildError>`, the load-phase shape) rather than
+    /// [`build()`](Self::build)'s `SchemaErrors` — `from_str` is a
+    /// load-phase API; only `build*` methods return `SchemaErrors`.
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// # use libgraphql_core_v1 as libgraphql_core;
+    /// use libgraphql_core::schema::SchemaBuilder;
+    ///
+    /// let builder = SchemaBuilder::from_str(
+    ///     "type Query { hello: String }",
+    /// ).unwrap();
+    /// let schema = builder.build().unwrap();
+    ///
+    /// assert!(schema.object_type("Query").is_some());
+    /// ```
+    // An inherent `from_str` is intentional (mirroring the other
+    // string entry points and the v0 API) rather than a
+    // `std::str::FromStr` impl, which would force callers to
+    // import the trait for a builder-construction convenience.
+    #[allow(clippy::should_implement_trait)]
+    pub fn from_str(source: &str) -> Result<Self, Vec<SchemaBuildError>> {
+        let mut builder = Self::new();
+        builder.load_str(source)?;
+        Ok(builder)
+    }
+
+    /// Like [`from_str()`](Self::from_str), but labels the
+    /// registered [`SchemaSourceMap`] with `label` (see
+    /// [`load_str_with_label()`](Self::load_str_with_label)).
+    pub fn from_str_with_label(
+        source: &str,
+        label: impl AsRef<Path>,
+    ) -> Result<Self, Vec<SchemaBuildError>> {
+        let mut builder = Self::new();
+        builder.load_str_with_label(source, label)?;
+        Ok(builder)
+    }
+
+    /// Shared implementation for the `load_str` family:
+    /// registers a [`SchemaSourceMap`] (labeled with `label`,
+    /// if provided) for `source`, parses it, and loads all
+    /// definitions into this builder.
+    fn load_str_impl(
+        &mut self,
+        source: &str,
+        label: Option<PathBuf>,
     ) -> Result<&mut Self, Vec<SchemaBuildError>> {
         let parse_result =
             libgraphql_parser::parse_schema(source);
@@ -434,7 +540,7 @@ impl SchemaBuilder {
             },
         };
         self.source_maps.push(
-            SchemaSourceMap::from_source(source, None),
+            SchemaSourceMap::from_source(source, label),
         );
 
         // Report parse-level errors with proper spans
@@ -791,11 +897,11 @@ impl SchemaBuilder {
     /// 3. **Empty type checks** -- rejects object/interface types
     ///    with no fields, unions with no members, and enums with
     ///    no values.
-    /// 4. **Type-system validators** -- runs
-    ///    [`ObjectOrInterfaceTypeValidator`],
-    ///    [`UnionTypeValidator`],
-    ///    [`InputObjectTypeValidator`], and
-    ///    [`validate_directive_definitions`] to enforce
+    /// 4. **Type-system validators** -- runs the (internal)
+    ///    `ObjectOrInterfaceTypeValidator`,
+    ///    `UnionTypeValidator`,
+    ///    `InputObjectTypeValidator`, and
+    ///    `validate_directive_definitions` passes to enforce
     ///    cross-type reference rules.
     ///
     /// See [Schema](https://spec.graphql.org/September2025/#sec-Schema).
@@ -1024,9 +1130,24 @@ impl SchemaBuilder {
     pub fn build_from_str(
         source: &str,
     ) -> Result<Schema, SchemaErrors> {
-        let mut sb = Self::new();
-        sb.load_str(source).map_err(SchemaErrors::new)?;
-        sb.build()
+        Self::from_str(source)
+            .map_err(SchemaErrors::new)
+            .and_then(Self::build)
+    }
+
+    /// Like [`build_from_str()`](Self::build_from_str), but
+    /// labels the registered [`SchemaSourceMap`] with `label`
+    /// (see [`load_str_with_label()`](Self::load_str_with_label)).
+    // TODO: SchemaErrors wraps Vec<SchemaBuildError> which is
+    // large. Consider boxing once error strategy is finalized.
+    #[allow(clippy::result_large_err)]
+    pub fn build_from_str_with_label(
+        source: &str,
+        label: impl AsRef<Path>,
+    ) -> Result<Schema, SchemaErrors> {
+        Self::from_str_with_label(source, label)
+            .map_err(SchemaErrors::new)
+            .and_then(Self::build)
     }
 
     // ---------------------------------------------------------
@@ -1107,15 +1228,6 @@ impl SchemaBuilder {
     pub(crate) fn errors(&self) -> &[SchemaBuildError] {
         &self.errors
     }
-
-    /// Returns the mutation root type name binding (for test
-    /// inspection).
-    // TODO: Remove #[allow(dead_code)] once mutation root type
-    // tests are added or build() consumes this field.
-    #[allow(dead_code)]
-    pub(crate) fn mutation_type_name(&self) -> Option<&(TypeName, Span)> {
-        self.mutation_type_name.as_ref()
-    }
 }
 
 // ---------------------------------------------------------

crates/libgraphql-core-v1/src/schema/schema_def.rs

@@ -1,6 +1,8 @@
 use crate::names::DirectiveName;
 use crate::names::TypeName;
+use crate::schema_source_map::LineCol;
 use crate::schema_source_map::SchemaSourceMap;
+use crate::span::Span;
 use crate::types::DirectiveDefinition;
 use crate::types::EnumType;
 use crate::types::GraphQLType;
@@ -265,4 +267,48 @@ impl Schema {
     pub fn source_maps(&self) -> &[SchemaSourceMap] {
         &self.source_maps
     }
+
+    // ---------------------------------------------------------
+    // Span resolution
+    // ---------------------------------------------------------
+
+    /// Resolves the start of a **schema-originated** [`Span`] to
+    /// a 0-based [`LineCol`] position using this schema's stored
+    /// source maps.
+    ///
+    /// # Accepted span domain
+    ///
+    /// This method only accepts spans that originated from this
+    /// `Schema` — i.e. spans found on its types, fields,
+    /// directive definitions, and the errors produced while
+    /// building it. A [`Span`]'s `source_map_id` is an index
+    /// that is only meaningful relative to the artifact that
+    /// produced it, so passing a span from any *other* artifact
+    /// (an operation, an executable document, or a different
+    /// `Schema`) yields `None` or a plausible-but-wrong
+    /// location.
+    ///
+    /// # Return value
+    ///
+    /// - `Some(LineCol)` for spans whose `source_map_id` is in
+    ///   range for this schema. Spans on built-in definitions
+    ///   (e.g. the `Boolean` scalar or `@skip` directive, which
+    ///   have no user-authored source) resolve against the
+    ///   synthetic built-in source map to line `0`, column `0`.
+    /// - `None` when the span's `source_map_id` is out of range
+    ///   for this schema.
+    ///
+    /// Because `Schema` does not retain source text, the
+    /// returned [`LineCol`]'s `col_utf8` always equals its
+    /// `col_linestart_byte_offset` (exact for ASCII source; a
+    /// byte-based approximation when the line contains
+    /// multi-byte characters).
+    pub fn resolve_span(&self, span: Span) -> Option<LineCol> {
+        let source_map = self.source_maps
+            .get(span.source_map_id.0 as usize)?;
+        Some(source_map.resolve_offset(
+            span.byte_span.start,
+            /* source = */ None,
+        ))
+    }
 }

crates/libgraphql-core-v1/src/schema/tests/mod.rs

@@ -1,5 +1,6 @@
 mod schema_build_error_tests;
 mod schema_builder_extension_tests;
 mod schema_builder_tests;
+mod schema_def_tests;
 mod schema_errors_tests;
 mod type_validation_error_tests;