test(ses): Coverage for module source validation (#2434)

## Description

This change increases coverage and consistency of error messages for
invalid module sources.

### Security Considerations

None.

### Scaling Considerations

None.

### Documentation Considerations

None.

### Testing Considerations

It’s tests all the way down.

### Compatibility Considerations

There is a possibility that this will break tests that are
over-constrained on error messages.

### Upgrade Considerations

None.

packages/ses/src/module-link.js

@@ -76,27 +76,27 @@ function mayBeVirtualModuleSource(moduleSource) {
 function validateVirtualModuleSource(moduleSource, moduleSpecifier) {
   const { exports } = moduleSource;
   isArray(exports) ||
-    Fail`Property 'exports' of a third-party module source must be an array, got ${q(
+    Fail`Invalid module source: 'exports' of a virtual module source must be an array, got ${q(
       exports,
     )}, for module ${q(moduleSpecifier)}`;
 }
 
 function validateModuleSource(moduleSource, moduleSpecifier) {
   isObject(moduleSource) ||
-    Fail`Module sources must be of type object, got ${q(
+    Fail`Invalid module source: must be of type object, got ${q(
       moduleSource,
     )}, for module ${q(moduleSpecifier)}`;
   const { imports, exports, reexports = [] } = moduleSource;
   isArray(imports) ||
-    Fail`Property 'imports' of a module source must be an array, got ${q(
+    Fail`Invalid module source: 'imports' must be an array, got ${q(
       imports,
     )}, for module ${q(moduleSpecifier)}`;
   isArray(exports) ||
-    Fail`Property 'exports' of a precompiled module source must be an array, got ${q(
+    Fail`Invalid module source: 'exports' must be an array, got ${q(
       exports,
     )}, for module ${q(moduleSpecifier)}`;
   isArray(reexports) ||
-    Fail`Property 'reexports' of a precompiled module source must be an array if present, got ${q(
+    Fail`Invalid module source: 'reexports' must be an array if present, got ${q(
       reexports,
     )}, for module ${q(moduleSpecifier)}`;
 }
@@ -138,9 +138,7 @@ export const instantiate = (
       resolvedImports,
     );
   } else {
-    throw TypeError(
-      `importHook must provide a module source, got ${q(moduleSource)}`,
-    );
+    throw TypeError(`Invalid module source, got ${q(moduleSource)}`);
   }
 
   // Memoize.

packages/ses/src/module-load.js

@@ -6,11 +6,13 @@ import {
   arrayJoin,
   arrayMap,
   arrayPush,
+  arraySome,
   create,
   freeze,
   generatorNext,
   generatorThrow,
   getOwnPropertyNames,
+  isArray,
   isObject,
   mapGet,
   mapHas,
@@ -85,14 +87,23 @@ const loadModuleSource = (
   moduleLoads,
   importMeta,
 ) => {
-  const { resolveHook } = weakmapGet(compartmentPrivateFields, compartment);
+  const { resolveHook, name: compartmentName } = weakmapGet(
+    compartmentPrivateFields,
+    compartment,
+  );
+
+  const { imports } = moduleSource;
+  if (
+    !isArray(imports) ||
+    arraySome(imports, specifier => typeof specifier !== 'string')
+  ) {
+    throw makeError(
+      X`Invalid module source: 'imports' must be an array of strings, got ${imports} for module ${q(moduleSpecifier)} of compartment ${q(compartmentName)}`,
+    );
+  }
 
   // resolve all imports relative to this referrer module.
-  const resolvedImports = resolveAll(
-    moduleSource.imports,
-    resolveHook,
-    moduleSpecifier,
-  );
+  const resolvedImports = resolveAll(imports, resolveHook, moduleSpecifier);
   const moduleRecord = freeze({
     compartment,
     moduleSource,

packages/ses/test/module-map.test.js

@@ -40,6 +40,77 @@ test('module map primed with module source descriptor with virtual module source
   t.is(index.default, 42);
 });
 
+test('module map primed with module source descriptor with no-imports virtual module source', async t => {
+  const compartment = new Compartment({
+    modules: {
+      './index.js': {
+        source: {},
+      },
+    },
+    resolveHook: specifier => specifier,
+    __noNamespaceBox__: true,
+    __options__: true,
+  });
+  await t.throwsAsync(() => compartment.import('./index.js'), {
+    message: /Invalid module source: 'imports' must be an array/,
+  });
+});
+
+test('module map primed with module source descriptor with imports-with-non-string virtual module source', async t => {
+  const compartment = new Compartment({
+    modules: {
+      './index.js': {
+        source: {
+          imports: [1],
+        },
+      },
+    },
+    resolveHook: specifier => specifier,
+    __noNamespaceBox__: true,
+    __options__: true,
+  });
+  await t.throwsAsync(() => compartment.import('./index.js'), {
+    message: /Invalid module source: 'imports' must be an array of strings/,
+  });
+});
+
+test('module map primed with module source descriptor with no-exports virtual module source', async t => {
+  const compartment = new Compartment({
+    modules: {
+      './index.js': {
+        source: {
+          imports: [],
+        },
+      },
+    },
+    resolveHook: specifier => specifier,
+    __noNamespaceBox__: true,
+    __options__: true,
+  });
+  await t.throwsAsync(() => compartment.import('./index.js'), {
+    message: /Invalid module source: 'exports' must be an array/,
+  });
+});
+
+test('module map primed with module source descriptor with no-execute virtual module source', async t => {
+  const compartment = new Compartment({
+    modules: {
+      './index.js': {
+        source: {
+          imports: [],
+          exports: [],
+        },
+      },
+    },
+    resolveHook: specifier => specifier,
+    __noNamespaceBox__: true,
+    __options__: true,
+  });
+  await t.throwsAsync(() => compartment.import('./index.js'), {
+    message: /Invalid module source/,
+  });
+});
+
 test('module map primed with parent compartment module source descriptor with string reference to parent compartment', async t => {
   const parent = new Compartment({
     modules: {