fix(typescript): break on multiple interface extends, fixes #2043 (#2085)

src/printer.js

@@ -826,7 +826,18 @@ function genericPrintNoParens(path, options, print, args) {
       );
 
       if (n.heritage.length) {
-        parts.push("extends ", join(", ", path.map(print, "heritage")), " ");
+        parts.push(
+          group(
+            indent(
+              concat([
+                softline,
+                "extends ",
+                indent(join(concat([",", line]), path.map(print, "heritage"))),
+                " "
+              ])
+            )
+          )
+        );
       }
 
       parts.push(path.call(print, "body"));

tests/typescript_interface/__snapshots__/jsfmt.spec.js.snap

@@ -22,6 +22,57 @@ interface ScreenObject {
 
 `;
 
+exports[`long-extends.ts 1`] = `
+export interface I extends A, B, C {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends ALongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends ALongAndBoringInterfaceName, AnotherLongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends AVeryLongAndBoringInterfaceName, AnotherVeryLongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends A_AVeryLongAndBoringInterfaceName, B_AVeryLongAndBoringInterfaceName, C_AVeryLongAndBoringInterfaceName  {
+  c: string;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+export interface I extends A, B, C {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName
+  extends ALongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName
+  extends ALongAndBoringInterfaceName,
+    AnotherLongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName
+  extends AVeryLongAndBoringInterfaceName,
+    AnotherVeryLongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName
+  extends A_AVeryLongAndBoringInterfaceName,
+    B_AVeryLongAndBoringInterfaceName,
+    C_AVeryLongAndBoringInterfaceName {
+  c: string;
+}
+
+`;
+
 exports[`separator.ts 1`] = `
 declare module 'selenium-webdriver' {
   export const until: {

tests/typescript_interface/long-extends.ts

@@ -0,0 +1,19 @@
+export interface I extends A, B, C {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends ALongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends ALongAndBoringInterfaceName, AnotherLongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends AVeryLongAndBoringInterfaceName, AnotherVeryLongAndBoringInterfaceName {
+  c: string;
+}
+
+export interface ThirdVeryLongAndBoringInterfaceName extends A_AVeryLongAndBoringInterfaceName, B_AVeryLongAndBoringInterfaceName, C_AVeryLongAndBoringInterfaceName  {
+  c: string;
+}