graphql_composition/
lib.rs

1#![deny(unsafe_code, missing_docs, rust_2018_idioms)]
2#![allow(clippy::option_option)]
3#![doc = include_str!("../README.md")]
4
5mod compose;
6mod composition_ir;
7mod diagnostics;
8mod emit_federated_graph;
9mod grafbase_extensions;
10mod ingest_subgraph;
11mod result;
12mod subgraphs;
13mod validate;
14
15pub use self::{
16    diagnostics::Diagnostics, grafbase_extensions::LoadedExtension, result::CompositionResult, subgraphs::IngestError,
17    subgraphs::Subgraphs,
18};
19pub use graphql_federated_graph::{
20    self as graphql_federated_graph, FederatedGraph, render_api_sdl, render_federated_sdl,
21};
22
23use self::{
24    compose::{ComposeContext, compose_subgraphs},
25    emit_federated_graph::emit_federated_graph,
26    ingest_subgraph::ast_value_to_subgraph_value,
27};
28
29/// Compose subgraphs into a federated graph.
30pub fn compose(subgraphs: &Subgraphs) -> CompositionResult {
31    let mut diagnostics = Diagnostics::default();
32
33    if subgraphs.iter_subgraphs().len() == 0 {
34        let error = "No graphs found for composition build. You must have at least one active graph.";
35        diagnostics.push_fatal(error.to_owned());
36
37        return CompositionResult {
38            federated_graph: None,
39            diagnostics,
40        };
41    }
42
43    let mut context = ComposeContext::new(subgraphs, &mut diagnostics);
44
45    validate::validate(&mut context);
46
47    if context.diagnostics.any_fatal() {
48        return CompositionResult {
49            federated_graph: None,
50            diagnostics,
51        };
52    }
53
54    for (_, directive) in subgraphs.iter_extra_directives_on_schema_definition() {
55        let subgraphs::DirectiveProvenance::Linked {
56            linked_schema_id,
57            is_composed_directive: _,
58        } = directive.provenance
59        else {
60            continue;
61        };
62
63        if let Some(extension_id) = context.get_extension_for_linked_schema(linked_schema_id) {
64            context.mark_used_extension(extension_id);
65        }
66    }
67    compose_subgraphs(&mut context);
68
69    if context.diagnostics.any_fatal() {
70        CompositionResult {
71            federated_graph: None,
72            diagnostics,
73        }
74    } else {
75        let federated_graph = emit_federated_graph(context.into_ir(), subgraphs);
76
77        CompositionResult {
78            federated_graph: Some(federated_graph),
79            diagnostics,
80        }
81    }
82}
83
84trait VecExt<T> {
85    fn push_return_idx(&mut self, elem: T) -> usize;
86}
87
88impl<T> VecExt<T> for Vec<T> {
89    fn push_return_idx(&mut self, elem: T) -> usize {
90        let idx = self.len();
91        self.push(elem);
92        idx
93    }
94}
95
96#[cfg(test)]
97mod tests {
98    use super::*;
99
100    #[test]
101    fn grafbase_schema_can_be_composed() {
102        use std::{fs, path::Path};
103        let schema_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("../../cli/src/api/graphql/api.graphql");
104        let schema = fs::read_to_string(schema_path).unwrap();
105
106        let mut subgraphs = Subgraphs::default();
107        subgraphs
108            .ingest_str(&schema, "grafbase-api", Some("https://api.grafbase.com"))
109            .unwrap();
110        let result = compose(&subgraphs);
111        assert!(!result.diagnostics().any_fatal());
112    }
113}
graphql_composition/lib.rs

graphql_composition/
lib.rs
