Fix aggregation of imports.

crates/wac-graph/Cargo.toml

@@ -28,6 +28,8 @@ wasmprinter = { workspace = true }
 wat = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
+wit-component = { workspace = true, features = ["dummy-module"] }
+wit-parser = { workspace = true }
 
 [features]
 serde = ["dep:serde", "wac-types/serde"]

crates/wac-graph/src/graph.rs

@@ -1351,6 +1351,7 @@ impl<'a> CompositionGraphEncoder<'a> {
         let mut arguments = Vec::new();
         let mut encoded = HashMap::new();
         let mut cache = Default::default();
+        let mut checker = SubtypeChecker::new(&mut cache);
 
         // Enumerate the instantiation nodes and populate the import types
         for node in self.0.nodes() {
@@ -1379,7 +1380,7 @@ impl<'a> CompositionGraphEncoder<'a> {
                 }
 
                 aggregator = aggregator
-                    .aggregate(name, package.types(), *kind, &mut cache)
+                    .aggregate(name, package.types(), *kind, &mut checker)
                     .map_err(|e| Error::ImportTypeMergeConflict {
                         import: name.clone(),
                         source: e,
@@ -1404,6 +1405,11 @@ impl<'a> CompositionGraphEncoder<'a> {
                 },
             );
 
+            // Ensure we insert an instance index into the current scope
+            if let ItemKind::Instance(id) = kind {
+                state.current.instances.insert(id, index);
+            }
+
             let prev = encoded.insert(name, (kind.into(), index));
             assert!(prev.is_none());
         }

crates/wac-graph/tests/encoding.rs

@@ -4,10 +4,13 @@ use semver::Version;
 use serde::Deserialize;
 use std::{
     collections::HashMap,
+    ffi::OsStr,
     fs::{self, File},
     path::{Path, PathBuf},
 };
 use wac_graph::{types::Package, CompositionGraph, EncodeOptions, NodeId, PackageId};
+use wit_component::{ComponentEncoder, StringEncoding};
+use wit_parser::Resolve;
 
 /// Represents a node to add to a composition graph.
 #[derive(Deserialize)]
@@ -118,12 +121,52 @@ impl GraphFile {
 
         for (index, package) in self.packages.iter().enumerate() {
             let path = root.join(&package.path);
-            let bytes = wat::parse_file(&path).with_context(|| {
-                format!(
-                    "failed to parse package `{path}` for test case `{test_case}`",
-                    path = path.display()
-                )
-            })?;
+            let bytes = match path.extension().and_then(OsStr::to_str) {
+                Some("wit") => {
+                    let mut resolve = Resolve::default();
+                    let id = resolve.push_file(&path).with_context(|| {
+                        format!(
+                            "failed to parse package file `{path}` for test case `{test_case}`",
+                            path = path.display()
+                        )
+                    })?;
+                    let world = resolve.select_world(id, None).with_context(|| {
+                        format!(
+                            "failed to select world from `{path}` for test case `{test_case}`",
+                            path = path.display()
+                        )
+                    })?;
+
+                    let mut module = wit_component::dummy_module(&resolve, world);
+                    wit_component::embed_component_metadata(
+                        &mut module,
+                        &resolve,
+                        world,
+                        StringEncoding::default(),
+                    )
+                    .with_context(|| {
+                        format!(
+                            "failed to embed component metadata from package `{path}` for test case `{test_case}`",
+                            path = path.display()
+                        )
+                    })?;
+
+                    let encoder = ComponentEncoder::default().validate(true).module(&module)?;
+                    encoder
+                        .encode()
+                        .with_context(|| format!("failed to encode a component from module derived from package `{path}` for test case `{test_case}`", path = path.display()))?
+                }
+                Some("wat") => wat::parse_file(&path).with_context(|| {
+                    format!(
+                        "failed to parse package `{path}` for test case `{test_case}`",
+                        path = path.display()
+                    )
+                })?,
+                _ => bail!(
+                    "unexpected file extension for package file `{path}`",
+                    path = package.path.display()
+                ),
+            };
 
             let package = Package::from_bytes(&package.name, package.version.as_ref(), bytes)
                 .with_context(|| {
@@ -226,6 +269,9 @@ impl GraphFile {
 /// * [required] `graph.json` - a JSON representation of a composition graph
 ///   (see above for serialization format).
 /// * [optional] `*.wat` - packages (i.e. components) referenced from `graph.json`.
+/// * [optional] `*.wit` - packages (i.e. components) referenced from `graph.json`;
+///   the file is expected to contain a single world representing the world of
+///   the component; a dummy module will be created to implement the component.
 ///
 /// And the output files are one of the following:
 ///

crates/wac-graph/tests/graphs/merged-usings/component.wit

@@ -0,0 +1,15 @@
+package foo:bar;
+
+interface baz {
+    resource x;
+}
+
+interface qux {
+    use baz.{x};
+    f: func() -> x;
+}
+
+world w {
+    import qux;
+    export qux;
+}

crates/wac-graph/tests/graphs/merged-usings/encoded.wat

@@ -0,0 +1,198 @@
+(component
+  (type (;0;)
+    (instance
+      (export (;0;) "x" (type (sub resource)))
+    )
+  )
+  (import "foo:bar/baz" (instance (;0;) (type 0)))
+  (alias export 0 "x" (type (;1;)))
+  (type (;2;)
+    (instance
+      (alias outer 1 1 (type (;0;)))
+      (export (;1;) "x" (type (eq 0)))
+      (type (;2;) (own 1))
+      (type (;3;) (func (result 2)))
+      (export (;0;) "f" (func (type 3)))
+    )
+  )
+  (import "foo:bar/qux" (instance (;1;) (type 2)))
+  (component (;0;)
+    (type (;0;)
+      (instance
+        (export (;0;) "x" (type (sub resource)))
+      )
+    )
+    (import "foo:bar/baz" (instance (;0;) (type 0)))
+    (alias export 0 "x" (type (;1;)))
+    (type (;2;)
+      (instance
+        (alias outer 1 1 (type (;0;)))
+        (export (;1;) "x" (type (eq 0)))
+        (type (;2;) (own 1))
+        (type (;3;) (func (result 2)))
+        (export (;0;) "f" (func (type 3)))
+      )
+    )
+    (import "foo:bar/qux" (instance (;1;) (type 2)))
+    (core module (;0;)
+      (type (;0;) (func (param i32)))
+      (type (;1;) (func (result i32)))
+      (type (;2;) (func (param i32 i32 i32 i32) (result i32)))
+      (import "foo:bar/baz" "[resource-drop]x" (func (;0;) (type 0)))
+      (import "foo:bar/qux" "f" (func (;1;) (type 1)))
+      (func (;2;) (type 1) (result i32)
+        unreachable
+      )
+      (func (;3;) (type 2) (param i32 i32 i32 i32) (result i32)
+        unreachable
+      )
+      (memory (;0;) 0)
+      (export "foo:bar/qux#f" (func 2))
+      (export "memory" (memory 0))
+      (export "cabi_realloc" (func 3))
+      (@producers
+        (processed-by "wit-component" "0.202.0")
+      )
+    )
+    (alias export 0 "x" (type (;3;)))
+    (core func (;0;) (canon resource.drop 3))
+    (core instance (;0;)
+      (export "[resource-drop]x" (func 0))
+    )
+    (alias export 1 "f" (func (;0;)))
+    (core func (;1;) (canon lower (func 0)))
+    (core instance (;1;)
+      (export "f" (func 1))
+    )
+    (core instance (;2;) (instantiate 0
+        (with "foo:bar/baz" (instance 0))
+        (with "foo:bar/qux" (instance 1))
+      )
+    )
+    (alias core export 2 "memory" (core memory (;0;)))
+    (alias core export 2 "cabi_realloc" (core func (;2;)))
+    (alias export 0 "x" (type (;4;)))
+    (type (;5;) (own 4))
+    (type (;6;) (func (result 5)))
+    (alias core export 2 "foo:bar/qux#f" (core func (;3;)))
+    (func (;1;) (type 6) (canon lift (core func 3)))
+    (alias export 0 "x" (type (;7;)))
+    (component (;0;)
+      (import "import-type-x" (type (;0;) (sub resource)))
+      (import "import-type-x0" (type (;1;) (eq 0)))
+      (type (;2;) (own 1))
+      (type (;3;) (func (result 2)))
+      (import "import-func-f" (func (;0;) (type 3)))
+      (export (;4;) "x" (type 0))
+      (type (;5;) (own 4))
+      (type (;6;) (func (result 5)))
+      (export (;1;) "f" (func 0) (func (type 6)))
+    )
+    (instance (;2;) (instantiate 0
+        (with "import-func-f" (func 1))
+        (with "import-type-x" (type 7))
+        (with "import-type-x0" (type 4))
+      )
+    )
+    (export (;3;) "foo:bar/qux" (instance 2))
+    (@producers
+      (processed-by "wit-component" "0.202.0")
+    )
+  )
+  (instance $component2 (;2;) (instantiate 0
+      (with "foo:bar/baz" (instance 0))
+      (with "foo:bar/qux" (instance 1))
+    )
+  )
+  (alias export $component2 "foo:bar/qux" (instance $alias (;3;)))
+  (component (;1;)
+    (type (;0;)
+      (instance
+        (export (;0;) "x" (type (sub resource)))
+      )
+    )
+    (import "foo:bar/baz" (instance (;0;) (type 0)))
+    (alias export 0 "x" (type (;1;)))
+    (type (;2;)
+      (instance
+        (alias outer 1 1 (type (;0;)))
+        (export (;1;) "x" (type (eq 0)))
+        (type (;2;) (own 1))
+        (type (;3;) (func (result 2)))
+        (export (;0;) "f" (func (type 3)))
+      )
+    )
+    (import "foo:bar/qux" (instance (;1;) (type 2)))
+    (core module (;0;)
+      (type (;0;) (func (param i32)))
+      (type (;1;) (func (result i32)))
+      (type (;2;) (func (param i32 i32 i32 i32) (result i32)))
+      (import "foo:bar/baz" "[resource-drop]x" (func (;0;) (type 0)))
+      (import "foo:bar/qux" "f" (func (;1;) (type 1)))
+      (func (;2;) (type 1) (result i32)
+        unreachable
+      )
+      (func (;3;) (type 2) (param i32 i32 i32 i32) (result i32)
+        unreachable
+      )
+      (memory (;0;) 0)
+      (export "foo:bar/qux#f" (func 2))
+      (export "memory" (memory 0))
+      (export "cabi_realloc" (func 3))
+      (@producers
+        (processed-by "wit-component" "0.202.0")
+      )
+    )
+    (alias export 0 "x" (type (;3;)))
+    (core func (;0;) (canon resource.drop 3))
+    (core instance (;0;)
+      (export "[resource-drop]x" (func 0))
+    )
+    (alias export 1 "f" (func (;0;)))
+    (core func (;1;) (canon lower (func 0)))
+    (core instance (;1;)
+      (export "f" (func 1))
+    )
+    (core instance (;2;) (instantiate 0
+        (with "foo:bar/baz" (instance 0))
+        (with "foo:bar/qux" (instance 1))
+      )
+    )
+    (alias core export 2 "memory" (core memory (;0;)))
+    (alias core export 2 "cabi_realloc" (core func (;2;)))
+    (alias export 0 "x" (type (;4;)))
+    (type (;5;) (own 4))
+    (type (;6;) (func (result 5)))
+    (alias core export 2 "foo:bar/qux#f" (core func (;3;)))
+    (func (;1;) (type 6) (canon lift (core func 3)))
+    (alias export 0 "x" (type (;7;)))
+    (component (;0;)
+      (import "import-type-x" (type (;0;) (sub resource)))
+      (import "import-type-x0" (type (;1;) (eq 0)))
+      (type (;2;) (own 1))
+      (type (;3;) (func (result 2)))
+      (import "import-func-f" (func (;0;) (type 3)))
+      (export (;4;) "x" (type 0))
+      (type (;5;) (own 4))
+      (type (;6;) (func (result 5)))
+      (export (;1;) "f" (func 0) (func (type 6)))
+    )
+    (instance (;2;) (instantiate 0
+        (with "import-func-f" (func 1))
+        (with "import-type-x" (type 7))
+        (with "import-type-x0" (type 4))
+      )
+    )
+    (export (;3;) "foo:bar/qux" (instance 2))
+    (@producers
+      (processed-by "wit-component" "0.202.0")
+    )
+  )
+  (instance $component1 (;4;) (instantiate 1
+      (with "foo:bar/qux" (instance $alias))
+      (with "foo:bar/baz" (instance 0))
+    )
+  )
+  (alias export $component1 "foo:bar/qux" (instance $export (;5;)))
+  (export (;6;) "foo:bar/qux" (instance $export))
+)