Print 3 or more chained calls on multiple lines (#2673)

src/printer.js

@@ -3464,11 +3464,7 @@ function printMemberLookup(path, options, print) {
     return concat([optional, ".", property]);
   }
 
-  if (
-    !n.property ||
-    (n.property.type === "Literal" && typeof n.property.value === "number") ||
-    n.property.type === "NumericLiteral"
-  ) {
+  if (!n.property || isNumericLiteral(n.property)) {
     return concat([optional, "[", property, "]"]);
   }
 
@@ -3585,14 +3581,16 @@ function printMemberChain(path, options, print) {
       break;
     }
   }
-  for (; i + 1 < printedNodes.length; ++i) {
-    if (
-      isMemberish(printedNodes[i].node) &&
-      isMemberish(printedNodes[i + 1].node)
-    ) {
-      currentGroup.push(printedNodes[i]);
-    } else {
-      break;
+  if (printedNodes[0].node.type !== "CallExpression") {
+    for (; i + 1 < printedNodes.length; ++i) {
+      if (
+        isMemberish(printedNodes[i].node) &&
+        isMemberish(printedNodes[i + 1].node)
+      ) {
+        currentGroup.push(printedNodes[i]);
+      } else {
+        break;
+      }
     }
   }
   groups.push(currentGroup);
@@ -3609,7 +3607,7 @@ function printMemberChain(path, options, print) {
       // beginning of the next one
       if (
         printedNodes[i].node.computed &&
-        isLiteral(printedNodes[i].node.property)
+        isNumericLiteral(printedNodes[i].node.property)
       ) {
         currentGroup.push(printedNodes[i]);
         continue;
@@ -3702,14 +3700,20 @@ function printMemberChain(path, options, print) {
     printIndentedGroup(groups.slice(shouldMerge ? 2 : 1))
   ]);
 
-  // If there's a comment, we don't want to print in one line.
-  if (hasComment) {
-    return group(expanded);
-  }
+  const callExpressionCount = printedNodes.filter(
+    tuple => tuple.node.type === "CallExpression"
+  ).length;
 
-  // If any group but the last one has a hard line, we want to force expand
-  // it. If the last group is a function it's okay to inline if it fits.
-  if (printedGroups.slice(0, -1).some(willBreak)) {
+  // We don't want to print in one line if there's:
+  //  * A comment.
+  //  * 3 or more chained calls.
+  //  * Any group but the last one has a hard line.
+  // If the last group is a function it's okay to inline if it fits.
+  if (
+    hasComment ||
+    callExpressionCount >= 3 ||
+    printedGroups.slice(0, -1).some(willBreak)
+  ) {
     return group(expanded);
   }
 
@@ -4724,6 +4728,13 @@ function isLiteral(node) {
   );
 }
 
+function isNumericLiteral(node) {
+  return (
+    node.type === "NumericLiteral" ||
+    (node.type === "Literal" && typeof node.value === "number")
+  );
+}
+
 function isStringLiteral(node) {
   return (
     node.type === "StringLiteral" ||

tests/flow/async_iteration/__snapshots__/jsfmt.spec.js.snap

@@ -153,11 +153,13 @@ async function* refuse_return() {
     return 0;
   }
 }
-refuse_return().return("string").then(result => {
-  if (result.done) {
-    (result.value: string); // error: number | void ~> string
-  }
-});
+refuse_return()
+  .return("string")
+  .then(result => {
+    if (result.done) {
+      (result.value: string); // error: number | void ~> string
+    }
+  });
 
 `;
 
@@ -204,11 +206,13 @@ async function* catch_return() {
 }
 
 async () => {
-  catch_return().throw("").then(({ value }) => {
-    if (value !== undefined) {
-      (value: void); // error: number ~> void
-    }
-  });
+  catch_return()
+    .throw("")
+    .then(({ value }) => {
+      if (value !== undefined) {
+        (value: void); // error: number ~> void
+      }
+    });
 };
 
 async function* yield_return() {
@@ -221,11 +225,13 @@ async function* yield_return() {
 }
 
 async () => {
-  yield_return().throw("").then(({ value }) => {
-    if (value !== undefined) {
-      (value: void); // error: number ~> void
-    }
-  });
+  yield_return()
+    .throw("")
+    .then(({ value }) => {
+      if (value !== undefined) {
+        (value: void); // error: number ~> void
+      }
+    });
 };
 
 `;

tests/flow/node_tests/crypto/__snapshots__/jsfmt.spec.js.snap

@@ -70,7 +70,10 @@ let tests = [
     hmac.update(buf, "utf8"); // 1 error: no encoding when passing a buffer
 
     // it's also chainable
-    (hmac.update("some data to hash").update(buf).digest(): Buffer);
+    (hmac
+      .update("some data to hash")
+      .update(buf)
+      .digest(): Buffer);
 
     (hmac.digest("hex"): string);
     (hmac.digest(): Buffer);

tests/flow/promises/__snapshots__/jsfmt.spec.js.snap

@@ -587,10 +587,12 @@ Promise.reject(0)
   });
 
 // resolvedPromise<T> -> catch() -> then():?T
-Promise.resolve(0).catch(function(err) {}).then(function(num) {
-  var a: ?number = num;
-  var b: string = num; // Error: string ~> number
-});
+Promise.resolve(0)
+  .catch(function(err) {})
+  .then(function(num) {
+    var a: ?number = num;
+    var b: string = num; // Error: string ~> number
+  });
 
 `;
 

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

@@ -27,10 +27,13 @@ const veryVeryVeryVeryVeryVeryVeryLong =
 const small = doc.expandedStates[doc.expandedStates.length - 1];
 
 const promises = [
-  promise.resolve().then(console.log).catch(err => {
-    console.log(err);
-    return null;
-  }),
+  promise
+    .resolve()
+    .then(console.log)
+    .catch(err => {
+      console.log(err);
+      return null;
+    }),
   redis.fetch(),
   other.fetch()
 ];

tests/method-chain/__snapshots__/jsfmt.spec.js.snap

@@ -205,6 +205,26 @@ const {
 
 `;
 
+exports[`break-multiple.js 1`] = `
+object.foo().bar().baz();
+
+foo().bar().baz();
+
+foo().bar.baz();
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+object
+  .foo()
+  .bar()
+  .baz();
+
+foo()
+  .bar()
+  .baz();
+
+foo().bar.baz();
+
+`;
+
 exports[`comment.js 1`] = `
 function f() {
   return observableFromSubscribeFunction()
@@ -519,14 +539,16 @@ if (testConfig.ENABLE_ONLINE_TESTS === "true") {
   describe("POST /users/me/pet", function() {
     it("saves pet", function() {
       function assert(pet) {
-        expect(pet).to.have.property("OwnerAddress").that.deep.equals({
-          AddressLine1: "Alexanderstrasse",
-          AddressLine2: "",
-          PostalCode: "10999",
-          Region: "Berlin",
-          City: "Berlin",
-          Country: "DE"
-        });
+        expect(pet)
+          .to.have.property("OwnerAddress")
+          .that.deep.equals({
+            AddressLine1: "Alexanderstrasse",
+            AddressLine2: "",
+            PostalCode: "10999",
+            Region: "Berlin",
+            City: "Berlin",
+            Country: "DE"
+          });
       }
     });
   });
@@ -557,7 +579,10 @@ method().then(x => x)
 ({}.a().b());
 ({}).a().b();
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-method().then(x => x)["abc"](x => x)[abc](x => x);
+method()
+  .then(x => x)
+  ["abc"](x => x)
+  [abc](x => x);
 
 ({}.a().b());
 ({}.a().b());

tests/method-chain/break-multiple.js

@@ -0,0 +1,5 @@
+object.foo().bar().baz();
+
+foo().bar().baz();
+
+foo().bar.baz();