feat(import-target): Add resolution error reason

Author: scagood

lib/util/check-existence.js

@@ -22,7 +22,7 @@ function markMissing(context, target) {
         loc: /** @type {import('eslint').AST.SourceLocation} */ (
             target.node.loc
         ),
-        messageId: "notFound",
+        messageId: target.resolveError ? "notFoundBecause" : "notFound",
         data: /** @type {Record<string, *>} */ (target),
     })
 }
@@ -86,4 +86,5 @@ exports.checkExistence = function checkExistence(context, targets) {
 
 exports.messages = {
     notFound: '"{{name}}" is not found.',
+    notFoundBecause: '"{{name}}" is not found.\n{{resolveError}}',
 }

lib/util/import-target.js

@@ -131,6 +131,12 @@ module.exports = class ImportTarget {
          */
         this.moduleName = this.getModuleName()
 
+        /**
+         * This is the full resolution failure reasons
+         * @type {string | null}
+         */
+        this.resolveError = null
+
         /**
          * The full path of this import target.
          * If the target is a module and it does not exist then this is `null`.
@@ -286,12 +292,25 @@ module.exports = class ImportTarget {
 
         const cwd = this.context.settings?.cwd ?? process.cwd()
         for (const directory of this.getPaths()) {
+            const baseDir = resolve(cwd, directory)
+
             try {
-                const baseDir = resolve(cwd, directory)
                 const resolved = requireResolve(baseDir, this.name)
                 if (typeof resolved === "string") return resolved
-            } catch {
-                continue
+            } catch (error) {
+                if (error instanceof Error === false) {
+                    throw error
+                }
+
+                // This is the usual error
+                if (
+                    error.message ===
+                    `Can't resolve '${this.name}' in '${baseDir}'`
+                ) {
+                    continue
+                }
+
+                this.resolveError = error.message
             }
         }
 

tests/fixtures/no-missing/node_modules/misconfigured-default/build/index.js

@@ -39,6 +39,7 @@ function fixture(name) {
     return path.resolve(__dirname, "../../fixtures/no-missing", name)
 }
 
+/** @type {import('eslint').RuleTester} */
 const ruleTester = new RuleTester({
     languageOptions: {
         sourceType: "module",
@@ -313,7 +314,17 @@ ruleTester.run("no-missing-import", rule, {
         {
             filename: fixture("test.js"),
             code: "import abcdef from 'esm-module/sub.mjs';",
-            errors: ['"esm-module/sub.mjs" is not found.'],
+            // errors: ['"esm-module/sub.mjs" is not found.'],
+            errors: [
+                {
+                    messageId: "notFoundBecause",
+                    data: {
+                        name: "esm-module/sub.mjs",
+                        resolveError:
+                            "Package path ./sub.mjs is not exported from package /home/scagood/github/open-source/eslint-plugin-n/tests/fixtures/no-missing/node_modules/esm-module (see exports field in /home/scagood/github/open-source/eslint-plugin-n/tests/fixtures/no-missing/node_modules/esm-module/package.json)",
+                    },
+                },
+            ],
         },
         {
             filename: fixture("test.js"),
@@ -393,6 +404,20 @@ ruleTester.run("no-missing-import", rule, {
             errors: ['"./A.js" is not found.'],
         },
 
+        {
+            filename: fixture("test.js"),
+            code: "import 'misconfigured-default';",
+            errors: [
+                {
+                    messageId: "notFoundBecause",
+                    data: {
+                        name: "misconfigured-default",
+                        resolveError: "Default condition should be last one",
+                    },
+                },
+            ],
+        },
+
         // import()
         ...(DynamicImportSupported
             ? [