Fixes #1023 - Load exceptions in user resolvers are not reported

tests/files/load-error-resolver.js

@@ -0,0 +1 @@
+throw new Error('TEST ERROR')

tests/src/core/resolve.js

@@ -118,6 +118,22 @@ describe('resolve', function () {
                       )).to.equal(utils.testFilePath('./jsx/MyCoolComponent.jsx'))
   })
 
+  it('reports load exception in a user resolver', function () {
+
+    const testContext = utils.testContext({ 'import/resolver': './load-error-resolver' })
+    const testContextReports = []
+    testContext.report = function (reportInfo) {
+      testContextReports.push(reportInfo)
+    }
+
+    expect(resolve( '../files/exception'
+                      , Object.assign({}, testContext, { getFilename: function () { return utils.getFilename('exception.js') } })
+                    )).to.equal(undefined)
+    expect(testContextReports[0]).to.be.an('object')
+    expect(testContextReports[0].message).to.equal('Resolve error: TEST ERROR')
+    expect(testContextReports[0].loc).to.eql({ line: 1, column: 0 })
+  })
+
   const caseDescribe = (!CASE_SENSITIVE_FS ? describe : describe.skip)
   caseDescribe('case sensitivity', function () {
     let file

utils/resolve.js

@@ -14,6 +14,20 @@ exports.CASE_SENSITIVE_FS = CASE_SENSITIVE_FS
 
 const fileExistsCache = new ModuleCache()
 
+function tryRequire(target) {
+  let resolved;
+  try {
+    // Check if the target exists
+    resolved = require.resolve(target);
+  } catch(e) {
+    // If the target does not exist then just return undefined
+    return undefined;
+  }
+
+  // If the target exists then return the loaded module
+  return require(resolved);
+}
+
 // http://stackoverflow.com/a/27382838
 exports.fileExistsWithCaseSync = function fileExistsWithCaseSync(filepath, cacheSettings) {
   // don't care if the FS is case-sensitive
@@ -135,27 +149,20 @@ function resolverReducer(resolvers, map) {
   throw new Error('invalid resolver config')
 }
 
+function getBaseDir(sourceFile) {
+  return pkgDir.sync(sourceFile) || process.cwd()
+}
 function requireResolver(name, sourceFile) {
   // Try to resolve package with conventional name
-  try {
-    return require(`eslint-import-resolver-${name}`)
-  } catch (err) { /* continue */ }
+  let resolver = tryRequire(`eslint-import-resolver-${name}`) ||
+    tryRequire(name) ||
+    tryRequire(path.resolve(getBaseDir(sourceFile), name))
 
-  // Try to resolve package with custom name (@myorg/resolver-name)
-  try {
-    return require(name)
-  } catch (err) { /* continue */ }
-
-  // Try to resolve package with path, relative to closest package.json
-  // or current working directory
-  try {
-    const baseDir = pkgDir.sync(sourceFile) || process.cwd()
-    // absolute paths ignore base, so this covers both
-    return require(path.resolve(baseDir, name))
-  } catch (err) { /* continue */ }
-
-  // all else failed
-  throw new Error(`unable to load resolver "${name}".`)
+  if (!resolver) {
+    throw new Error(`unable to load resolver "${name}".`)
+  } else {
+    return resolver;
+  }
 }
 
 const erroredContexts = new Set()