graphql_composition/
lib.rs

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

graphql_composition/
lib.rs
