Fixed inference when using npm packages

.gitignore

@@ -1,4 +1,4 @@
-/node_modules
+node_modules/
 /target
 .vscode/
 vendor/

README.md

@@ -127,7 +127,6 @@ Limitations:
 * Functions can be executed via both the `/query` and `/mutation` endpoints
 * Conflicting type names in dependencies will be namespaced with their relative path
 * Generic type parameters will be treated as scalars when referenced
-* Deno's `npm:` specifier doesn't currently work with the vendor command
 
 Please [file an issue](https://github.com/hasura/ndc-typescript-deno/issues/new) for any problems you encounter during usage of this connector.
 
@@ -343,7 +342,7 @@ In order to perform local development on this codebase:
 
 * Check out the repository: `git clone https://github.com/hasura/ndc-typescript-deno.git`
 * This assumes that you will be testing against function in `./functions`
-* Vendor the dependencies with `cd ./function && deno vendor -f index.ts`
+* Vendor the dependencies with `cd ./function && deno vendor --node-modules-dir -f index.ts`
 * Serve your functions with `deno run -A --watch --check ./src/mod.ts serve --configuration <(echo '{"functions": "./functions/index.ts", "vendor": "./functions/vendor", "schemaMode": "INFER"}')`
 * The connector should now be running on localhost:8100 and respond to any changes to the your functions and the connector source
 * Use the `hasura3` tunnel commands to reference this connector from a Hasura Cloud project

src/entrypoint.sh

@@ -14,7 +14,7 @@ if [ -d vendor ]
 then
   echo "found existing vendor results"
 else
-  deno vendor -f index.ts
+  deno vendor --node-modules-dir -f index.ts
   deno vendor -f /app/mod.ts
 fi
 

src/infer.ts

@@ -8,7 +8,7 @@
  * Dependencies are required to be vendored before invocation. 
  */
 
-import ts, { FunctionDeclaration } from "npm:[email protected]";
+import ts, { FunctionDeclaration, StringLiteralLike } from "npm:[email protected]";
 import { resolve, dirname } from "https://deno.land/[email protected]/path/mod.ts";
 import { existsSync } from "https://deno.land/[email protected]/fs/mod.ts";
 import * as sdk from 'npm:@hasura/[email protected]';
@@ -187,7 +187,7 @@ function pre_vendor(vendorPath: string, filename: string) {
   // Exampe taken from:
   // https://docs.deno.com/runtime/tutorials/subprocess
   const deno_exec_path = Deno.execPath();
-  const vendor_args = [ "vendor", "--output", vendorPath, "--force", filename ];
+  const vendor_args = [ "vendor", "--node-modules-dir", "--output", vendorPath, "--force", filename ];
 
   console.error(`Vendoring dependencies: ${[deno_exec_path, ...vendor_args].join(" ")}`);
 
@@ -370,9 +370,9 @@ export function programInfoException(filename_arg?: string, vendor_arg?: string,
   }
   `);
 
-  const program = ts.createProgram([filename], {
+  const compilerOptions: ts.CompilerOptions = {
     // This should match the version targeted in the deno version that is being used.
-    target: ts.ScriptTarget.ES2022,
+    target: ts.ScriptTarget.ES5,
     module: ts.ModuleKind.CommonJS,
     noImplicitAny: true,
     // NOTE: We just declare Deno globally as any in order to allow users to omit it's declaration in their function files
@@ -383,7 +383,26 @@ export function programInfoException(filename_arg?: string, vendor_arg?: string,
     noEmit: true,
     baseUrl: '.',
     paths: pathsMap
-  });
+  };
+
+  const host = ts.createCompilerHost(compilerOptions);
+  host.resolveModuleNameLiterals = (moduleLiterals: StringLiteralLike[], containingFile: string): ts.ResolvedModuleWithFailedLookupLocations[] => {
+    return moduleLiterals.map(moduleName => {
+      let moduleNameToResolve = moduleName.text;
+      // If this looks like a Deno "npm:pkgName[@version][/path]" module import, extract the node module
+      // name and resolve that instead. So long as we've done a deno vendor with --node-modules-dir
+      // then we'll have a node_modules directory that the standard TypeScript module resolution
+      // process can locate the npm package in by its name
+      const npmDepMatch = /^npm:(?<pkgName>(?:@.+?\/)?[^/\n]+?)(?:@.+)?(?:\/.+)?$/.exec(moduleName.text);
+      if (npmDepMatch) {
+        moduleNameToResolve = npmDepMatch.groups?.pkgName!;
+      }
+
+      return ts.resolveModuleName(moduleNameToResolve, containingFile, compilerOptions, { fileExists: host.fileExists, readFile: host.readFile });
+    })
+  }
+
+  const program = ts.createProgram([filename], compilerOptions, host);
 
   Deno.removeSync(deno_d_ts);
 
@@ -535,4 +554,3 @@ export function programInfoException(filename_arg?: string, vendor_arg?: string,
 
   return result;
 }
-

src/test/external_dependencies_test.ts

@@ -6,22 +6,44 @@ import * as infer   from '../infer.ts';
 // Skipped due to NPM dependency resolution not currently being supported.
 Deno.test({
   name: "Inference",
-  ignore: true,
   fn() {
     const program_path = path.fromFileUrl(import.meta.resolve('./data/external_dependencies.ts'));
     const vendor_path = path.fromFileUrl(import.meta.resolve('./vendor'));
-    const program_results = infer.programInfo(program_path, vendor_path, false);
+    const program_results = infer.programInfo(program_path, vendor_path, true);
 
     test.assertEquals(program_results, {
       positions: {
+        test_deps: [
+          "s"
+        ]
       },
       schema: {
         scalar_types: {
+          String: {
+            aggregate_functions: {},
+            comparison_operators: {},
+            update_operators: {},
+          },
         },
         object_types: {},
         collections: [],
         functions: [],
         procedures: [
+          {
+            name: "test_deps",
+            arguments: {
+              s: {
+                type: {
+                  name: "String",
+                  type: "named",
+                },
+              },
+            },
+            result_type: {
+              name: "String",
+              type: "named",
+            },
+          },
         ],
       }
     });