resolveToValue resolves to ImportSpecifiers

Author: danez

Diff for: .changeset/four-teachers-tan.md

@@ -0,0 +1,20 @@
+---
+'react-docgen': major
+---
+
+`resolveToValue` will not resolve to `ImportDeclaration` anymore but instead to
+one of the possible specifiers (`ImportSpecifier`, `ImportDefaultSpecifier` or
+`ImportNamespaceSpecifier`). This gives better understanding to which specifier
+exactly `resolveToValue` did resolve a NodePath to.
+
+Here is a possible easy fix for this in a code snippet that uses
+`resolveToValue`
+
+```diff
+const resolved = resolveToValue(path);
+
+-if (resolved.isImportDeclaration()) {
++if (resolved.parentPath?.isImportDeclaration()) {
+    // do smth
+}
+```

Diff for: packages/react-docgen/src/handlers/defaultPropsHandler.ts

@@ -38,7 +38,7 @@ function getDefaultValue(path: NodePath): DefaultValueDescriptor | null {
     } else {
       resolvedPath = resolveToValue(path);
     }
-    if (resolvedPath.isImportDeclaration() && path.isIdentifier()) {
+    if (resolvedPath.parentPath?.isImportDeclaration() && path.isIdentifier()) {
       defaultValue = path.node.name;
     } else {
       valuePath = resolvedPath;

Diff for: packages/react-docgen/src/utils/__tests__/isUnreachableFlowType-test.ts

@@ -1,3 +1,4 @@
+import { ImportDeclaration } from '@babel/types';
 import { parse } from '../../../tests/utils';
 import isUnreachableFlowType from '../isUnreachableFlowType.js';
 import { describe, expect, test } from 'vitest';
@@ -7,10 +8,14 @@ describe('isUnreachableFlowType', () => {
     expect(isUnreachableFlowType(parse.expression('foo'))).toBe(true);
   });
 
-  test('considers ImportDeclaration as unreachable', () => {
-    expect(isUnreachableFlowType(parse.statement('import x from "";'))).toBe(
-      true,
-    );
+  test('considers any ImportSpecifier as unreachable', () => {
+    expect(
+      isUnreachableFlowType(
+        parse
+          .statement<ImportDeclaration>('import x from "";')
+          .get('specifiers')[0],
+      ),
+    ).toBe(true);
   });
 
   test('considers CallExpression as unreachable', () => {

Diff for: packages/react-docgen/src/utils/__tests__/resolveToValue-test.ts

@@ -157,7 +157,7 @@ describe('resolveToValue', () => {
       );
       const value = resolveToValue(path);
 
-      expect(value.node.type).toBe('ImportDeclaration');
+      expect(value.node.type).toBe('ImportDefaultSpecifier');
     });
 
     test('resolves unresolvable named import references to the import declaration', () => {
@@ -166,7 +166,7 @@ describe('resolveToValue', () => {
       );
       const value = resolveToValue(path);
 
-      expect(value.node.type).toBe('ImportDeclaration');
+      expect(value.node.type).toBe('ImportSpecifier');
     });
 
     test('resolves unresolvable aliased import references to the import declaration', () => {
@@ -175,7 +175,7 @@ describe('resolveToValue', () => {
       );
       const value = resolveToValue(path);
 
-      expect(value.node.type).toBe('ImportDeclaration');
+      expect(value.node.type).toBe('ImportSpecifier');
     });
 
     test('resolves unresolvable namespace import references to the import declaration', () => {
@@ -184,7 +184,7 @@ describe('resolveToValue', () => {
       );
       const value = resolveToValue(path);
 
-      expect(value.node.type).toBe('ImportDeclaration');
+      expect(value.node.type).toBe('ImportNamespaceSpecifier');
     });
 
     test('resolves namespace import references to the import declaration', () => {

Diff for: packages/react-docgen/src/utils/getPropType.ts

@@ -37,7 +37,9 @@ function getEnumValuesFromArrayExpression(
     const value = resolveToValue(elementPath as NodePath<Expression>);
 
     return values.push({
-      value: printValue(value.isImportDeclaration() ? elementPath : value),
+      value: printValue(
+        value.parentPath?.isImportDeclaration() ? elementPath : value,
+      ),
       computed: !value.isLiteral(),
     });
   });

Diff for: packages/react-docgen/src/utils/isUnreachableFlowType.ts

@@ -2,9 +2,12 @@ import type { NodePath } from '@babel/traverse';
 
 /**
  * Returns true of the path is an unreachable TypePath
+ * This evaluates the NodePaths returned from resolveToValue
  */
 export default (path: NodePath): boolean => {
   return (
-    path.isIdentifier() || path.isImportDeclaration() || path.isCallExpression()
+    path.isIdentifier() ||
+    path.parentPath?.isImportDeclaration() ||
+    path.isCallExpression()
   );
 };

Diff for: packages/react-docgen/src/utils/resolveToModule.ts

@@ -32,8 +32,8 @@ export default function resolveToModule(path: NodePath): string | null {
     }
   } else if (path.isObjectProperty() || path.isObjectPattern()) {
     return resolveToModule(path.parentPath);
-  } else if (path.isImportDeclaration()) {
-    return path.node.source.value;
+  } else if (path.parentPath?.isImportDeclaration()) {
+    return path.parentPath.node.source.value;
   } else if (path.isMemberExpression()) {
     path = getMemberExpressionRoot(path);
 

Diff for: packages/react-docgen/src/utils/resolveToValue.ts

@@ -188,11 +188,17 @@ export default function resolveToValue(path: NodePath): NodePath {
           return resolveToValue(memberPath);
         }
       }
-    } else if (resolved.isImportDeclaration() && resolved.node.specifiers) {
+    } else if (
+      resolved.isImportSpecifier() ||
+      resolved.isImportDefaultSpecifier() ||
+      resolved.isImportNamespaceSpecifier()
+    ) {
+      const declaration = resolved.parentPath as NodePath<ImportDeclaration>;
+
       // Handle references to namespace imports, e.g. import * as foo from 'bar'.
       // Try to find a specifier that matches the root of the member expression, and
       // find the export that matches the property name.
-      for (const specifier of resolved.get('specifiers')) {
+      for (const specifier of declaration.get('specifiers')) {
         const property = path.get('property');
         let propertyName: string | undefined;
 
@@ -206,21 +212,14 @@ export default function resolveToValue(path: NodePath): NodePath {
           propertyName &&
           specifier.node.local.name === root.node.name
         ) {
-          const resolvedPath = path.hub.import(resolved, propertyName);
+          const resolvedPath = path.hub.import(declaration, propertyName);
 
           if (resolvedPath) {
             return resolveToValue(resolvedPath);
           }
         }
       }
     }
-  } else if (
-    path.isImportDefaultSpecifier() ||
-    path.isImportNamespaceSpecifier() ||
-    path.isImportSpecifier()
-  ) {
-    // go up to the import declaration
-    return path.parentPath;
   } else if (
     path.isTypeCastExpression() ||
     path.isTSAsExpression() ||