Fix VS Code module path resolution (#62)

Author: disjukr

bdl-vscode/src/context.ts

@@ -6,6 +6,7 @@ import { type BdlConfig } from "@disjukr/bdl/io/config";
 import { type BdlStandard } from "@disjukr/bdl/io/standard";
 import parseBdl from "@disjukr/bdl/parser";
 import builtinStandards from "@disjukr/bdl/builtin/standards";
+import { resolveModulePath } from "./module-path.ts";
 
 export class BdlShortTermContext {
   #workspaceFolder: vscode.WorkspaceFolder | undefined;
@@ -134,10 +135,12 @@ export class BdlShortTermDocumentContext {
       const pathEntries = Object.entries(bdlConfig.paths);
       for (const [packageName, packagePath] of pathEntries) {
         const absPkgPath = vscode.Uri.joinPath(cfgDir, packagePath).path;
-        if (documentPath.startsWith(absPkgPath)) {
-          const subPath = documentPath.slice(absPkgPath.length);
-          const names = subPath.split("/").filter(Boolean);
-          const modulePath = `${packageName}.${names.join(".")}`;
+        const modulePath = resolveModulePath(
+          packageName,
+          absPkgPath,
+          documentPath,
+        );
+        if (modulePath) {
           this.#moduleInfo = { success: true, packageName, modulePath };
           break get;
         }

bdl-vscode/src/module-path.test.ts

@@ -0,0 +1,35 @@
+import { assertEquals } from "jsr:@std/assert@1";
+import { resolveModulePath } from "./module-path.ts";
+
+Deno.test("resolveModulePath strips the .bdl extension", () => {
+  assertEquals(
+    resolveModulePath(
+      "pkg",
+      "/workspace/schemas/pkg",
+      "/workspace/schemas/pkg/foo/bar.bdl",
+    ),
+    "pkg.foo.bar",
+  );
+});
+
+Deno.test("resolveModulePath rejects sibling package prefixes", () => {
+  assertEquals(
+    resolveModulePath(
+      "pkg",
+      "/workspace/schemas/pkg",
+      "/workspace/schemas/pkg-extra/foo.bdl",
+    ),
+    undefined,
+  );
+});
+
+Deno.test("resolveModulePath ignores non-bdl documents", () => {
+  assertEquals(
+    resolveModulePath(
+      "pkg",
+      "/workspace/schemas/pkg",
+      "/workspace/schemas/pkg/foo/bar.json",
+    ),
+    undefined,
+  );
+});

bdl-vscode/src/module-path.ts

@@ -0,0 +1,23 @@
+export function resolveModulePath(
+  packageName: string,
+  packageRootPath: string,
+  documentPath: string,
+): string | undefined {
+  const normalizedPackageRoot = packageRootPath.endsWith("/")
+    ? packageRootPath.slice(0, -1)
+    : packageRootPath;
+  const packagePrefix = `${normalizedPackageRoot}/`;
+  if (!documentPath.startsWith(packagePrefix)) return undefined;
+
+  const relativeDocumentPath = documentPath.slice(packagePrefix.length);
+  if (!relativeDocumentPath.endsWith(".bdl")) return undefined;
+
+  const relativeModulePath = relativeDocumentPath
+    .slice(0, -".bdl".length)
+    .split("/")
+    .filter(Boolean)
+    .join(".");
+  if (!relativeModulePath) return undefined;
+
+  return `${packageName}.${relativeModulePath}`;
+}