fix(eslint-plugin): [no-throw-literal] fix crash caused by getBaseTypes (typescript-eslint#1830)

a-tarasyuk · web-flow · commit 9d53c761983d · 2020-04-01T08:41:44.000-07:00
diff --git a/packages/eslint-plugin/src/rules/no-throw-literal.ts b/packages/eslint-plugin/src/rules/no-throw-literal.ts
@@ -43,10 +43,11 @@ export default util.createRule({
         }
       }
 
-      const baseTypes = checker.getBaseTypes(type as ts.InterfaceType);
-      for (const baseType of baseTypes) {
-        if (isErrorLike(baseType)) {
-          return true;
+      if (symbol.flags & (ts.SymbolFlags.Class | ts.SymbolFlags.Interface)) {
+        for (const baseType of checker.getBaseTypes(type as ts.InterfaceType)) {
+          if (isErrorLike(baseType)) {
+            return true;
+          }
         }
       }
 
diff --git a/packages/eslint-plugin/tests/rules/no-throw-literal.test.ts b/packages/eslint-plugin/tests/rules/no-throw-literal.test.ts
@@ -321,5 +321,36 @@ throw new CustomError();
         },
       ],
     },
+    {
+      code: `
+function foo<T>() {
+  const res: T;
+  throw res;
+}
+      `,
+      errors: [
+        {
+          messageId: 'object',
+          line: 4,
+          column: 9,
+        },
+      ],
+    },
+    {
+      code: `
+function foo<T>(fn: () => Promise<T>) {
+  const promise = fn();
+  const res = promise.then(() => {}).catch(() => {});
+  throw res;
+}
+      `,
+      errors: [
+        {
+          messageId: 'object',
+          line: 5,
+          column: 9,
+        },
+      ],
+    },
   ],
 });

Original file line number	Diff line number	Diff line change
`@@ -43,10 +43,11 @@ export default util.createRule({`
`43`	`43`	`}`
`44`	`44`	`}`
`45`	`45`
`46`		`- const baseTypes = checker.getBaseTypes(type as ts.InterfaceType);`
`47`		`- for (const baseType of baseTypes) {`
`48`		`- if (isErrorLike(baseType)) {`
`49`		`- return true;`
	`46`	`+ if (symbol.flags & (ts.SymbolFlags.Class \| ts.SymbolFlags.Interface)) {`
	`47`	`+ for (const baseType of checker.getBaseTypes(type as ts.InterfaceType)) {`
	`48`	`+ if (isErrorLike(baseType)) {`
	`49`	`+ return true;`
	`50`	`+ }`
`50`	`51`	`}`
`51`	`52`	`}`
`52`	`53`