Add additional error context to ComponentEncoder::encode (#1474)

* Add additional error context to ComponentEncoder::encode

Signed-off-by: Ryan Levick <ryan.levick@fermyon.com>

* Update tests

Signed-off-by: Ryan Levick <ryan.levick@fermyon.com>

---------

Signed-off-by: Ryan Levick <ryan.levick@fermyon.com>

Author: rylev

crates/wit-component/src/encoding.rs

@@ -2078,7 +2078,7 @@ impl ComponentEncoder {
             bail!("a module is required when encoding a component");
         }
 
-        let world = ComponentWorld::new(self)?;
+        let world = ComponentWorld::new(self).context("failed to decode world from module")?;
         let mut state = EncodingState {
             component: ComponentBuilder::default(),
             module_index: None,

crates/wit-component/src/encoding/world.rs

@@ -76,7 +76,8 @@ impl<'a> ComponentWorld<'a> {
             &encoder.metadata,
             &encoder.main_module_exports,
             &adapters,
-        )?;
+        )
+        .context("module was not valid")?;
 
         let mut ret = ComponentWorld {
             encoder,

crates/wit-component/tests/components/error-default-export-sig-mismatch/error.txt

@@ -1 +1,5 @@
-type mismatch for function `a`: expected `[I32, I32] -> [I32]` but found `[] -> []`
+failed to decode world from module
+
+Caused by:
+    0: module was not valid
+    1: type mismatch for function `a`: expected `[I32, I32] -> [I32]` but found `[] -> []`

crates/wit-component/tests/components/error-empty-module-import/error.txt

@@ -1 +1,5 @@
-no top-level imported function `foo` specified
+failed to decode world from module
+
+Caused by:
+    0: module was not valid
+    1: no top-level imported function `foo` specified

crates/wit-component/tests/components/error-export-sig-mismatch/error.txt

@@ -1,4 +1,6 @@
-failed to validate exported interface `foo`
+failed to decode world from module
 
 Caused by:
-    type mismatch for function `a`: expected `[I32, I32] -> [I32]` but found `[] -> []`
+    0: module was not valid
+    1: failed to validate exported interface `foo`
+    2: type mismatch for function `a`: expected `[I32, I32] -> [I32]` but found `[] -> []`

crates/wit-component/tests/components/error-import-resource-rep/error.txt

@@ -1 +1,5 @@
-no top-level imported function `[resource-rep]a` specified
+failed to decode world from module
+
+Caused by:
+    0: module was not valid
+    1: no top-level imported function `[resource-rep]a` specified

crates/wit-component/tests/components/error-import-resource-wrong-signature/error.txt

@@ -1 +1,5 @@
-type mismatch for function `[resource-drop]a`: expected `[I32] -> []` but found `[I32] -> [I32]`
+failed to decode world from module
+
+Caused by:
+    0: module was not valid
+    1: type mismatch for function `[resource-drop]a`: expected `[I32] -> []` but found `[I32] -> [I32]`

crates/wit-component/tests/components/error-import-sig-mismatch/error.txt

@@ -1,4 +1,6 @@
-failed to validate import interface `foo`
+failed to decode world from module
 
 Caused by:
-    type mismatch for function `bar`: expected `[I32, I32] -> []` but found `[] -> []`
+    0: module was not valid
+    1: failed to validate import interface `foo`
+    2: type mismatch for function `bar`: expected `[I32, I32] -> []` but found `[] -> []`

crates/wit-component/tests/components/error-invalid-module-import/error.txt

@@ -1 +1,5 @@
-module is only allowed to import functions
+failed to decode world from module
+
+Caused by:
+    0: module was not valid
+    1: module is only allowed to import functions

crates/wit-component/tests/components/error-missing-default-export/error.txt

@@ -1 +1,5 @@
-module does not export required function `a`
+failed to decode world from module
+
+Caused by:
+    0: module was not valid
+    1: module does not export required function `a`