Simplify isReferencedInExport and report types-in-types (resolves #830)

Author: webpro

packages/knip/src/types/config.ts

@@ -40,7 +40,7 @@ export type IgnorePatterns = (string | RegExp)[];
 
 type IgnorableExport = 'class' | 'enum' | 'function' | 'interface' | 'member' | 'type';
 
-export type IgnoreExportsUsedInFile = boolean | Partial<Record<IgnorableExport, boolean>>;
+type IgnoreExportsUsedInFile = boolean | Partial<Record<IgnorableExport, boolean>>;
 
 export type GetImportsAndExportsOptions = {
   skipTypeOnly: boolean;
@@ -68,7 +68,7 @@ export interface Configuration {
   rootPluginConfigs: Partial<PluginsConfiguration>;
 }
 
-export type NormalizedGlob = string[];
+type NormalizedGlob = string[];
 
 export type EnsuredPluginConfiguration = {
   config: NormalizedGlob | null;

packages/knip/src/typescript/ast-helpers.ts

@@ -201,26 +201,15 @@ export const isImportSpecifier = (node: ts.Node) =>
   ts.isImportClause(node.parent) ||
   ts.isNamespaceImport(node.parent);
 
-const isExported = (node: ts.Node): boolean => {
+const isInExportedNode = (node: ts.Node): boolean => {
   if (getExportKeywordNode(node)) return true;
-  return node.parent ? isExported(node.parent) : false;
-};
-
-const isTypeDeclaration = (node: ts.Node) =>
-  ts.isInterfaceDeclaration(node) || ts.isTypeAliasDeclaration(node) || ts.isEnumDeclaration(node);
-
-const getAncestorTypeDeclaration = (node: ts.Node) => {
-  while (node) {
-    if (isTypeDeclaration(node)) return node;
-    node = node.parent;
-  }
+  return node.parent ? isInExportedNode(node.parent) : false;
 };
 
 export const isReferencedInExport = (node: ts.Node) => {
-  if (ts.isTypeQueryNode(node.parent) && isExported(node.parent.parent)) return true;
-  if (ts.isTypeReferenceNode(node.parent) && isExported(node.parent.parent)) return true;
-  const typeNode = getAncestorTypeDeclaration(node);
-  return Boolean(typeNode && isExported(typeNode));
+  if (ts.isTypeQueryNode(node.parent) && isInExportedNode(node.parent.parent)) return true;
+  if (ts.isTypeReferenceNode(node.parent) && isInExportedNode(node.parent.parent)) return true;
+  return false;
 };
 
 export const getExportKeywordNode = (node: ts.Node) =>

packages/knip/src/typescript/find-internal-references.ts

@@ -41,7 +41,6 @@ export const findInternalReferences = (
 
           if (item.symbol === symbol) {
             refCount++;
-            if (isInExport || isType(item)) return [refCount, isSymbolInExport];
             if (isBindingElement) return [refCount, true];
           }
 

packages/knip/src/typescript/get-imports-and-exports.ts

@@ -399,7 +399,7 @@ const getImportsAndExports = (
   // and whether it's referenced in an exported type and should be exported with it (*)
   for (const item of exports.values()) {
     // TODO Reconsider this messy logic in AST visitors + `isReferencedInExport` + `findInternalReferences`
-    if (item.symbol && referencedSymbolsInExport.has(item.symbol)) {
+    if (!isType(item) && item.symbol && referencedSymbolsInExport.has(item.symbol)) {
       item.refs = [1, true];
     } else {
       const isBindingElement = item.symbol?.valueDeclaration && ts.isBindingElement(item.symbol.valueDeclaration);
@@ -408,7 +408,6 @@ const getImportsAndExports = (
         (typeof ignoreExportsUsedInFile === 'object' &&
           item.type !== 'unknown' &&
           ignoreExportsUsedInFile[item.type]) ||
-        isType(item) ||
         isBindingElement
       ) {
         item.refs = findInternalReferences(item, sourceFile, typeChecker, referencedSymbolsInExport, isBindingElement);

packages/knip/test/exports-value-refs-default.test.ts

@@ -14,10 +14,12 @@ test('Find unused exports in exported types (default)', async () => {
   });
 
   assert(issues.exports['refs.ts']['logger']);
+  assert(issues.types['refs.ts']['Lizard']);
 
   assert.deepEqual(counters, {
     ...baseCounters,
     exports: 1,
+    types: 1,
     processed: 2,
     total: 2,
   });