From f93fa28c908cbc6170551465fd946d0bc4602285 Mon Sep 17 00:00:00 2001
From: James DiGioia <jamesorodig@gmail.com>
Date: Fri, 6 Jul 2018 13:01:35 -0400
Subject: [PATCH] Improve error messages around pipeline option (#8279)

---
 .../babel-plugin-syntax-pipeline-operator/src/index.js   | 9 +++++++--
 packages/babel-preset-stage-0/src/index.js               | 6 ++++--
 packages/babel-preset-stage-1/src/index.js               | 7 +++++--
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/packages/babel-plugin-syntax-pipeline-operator/src/index.js b/packages/babel-plugin-syntax-pipeline-operator/src/index.js
index ae371a3792..9d58042b20 100644
--- a/packages/babel-plugin-syntax-pipeline-operator/src/index.js
+++ b/packages/babel-plugin-syntax-pipeline-operator/src/index.js
@@ -1,12 +1,17 @@
 import { declare } from "@babel/helper-plugin-utils";
 
-const proposals = ["minimal"];
+export const proposals = ["minimal"];
 
 export default declare((api, { proposal }) => {
   api.assertVersion(7);
 
   if (typeof proposal !== "string" || !proposals.includes(proposal)) {
-    throw new Error("'proposal' must be one of: " + proposals.join(", "));
+    throw new Error(
+      "The pipeline operator plugin requires a 'proposal' option." +
+        "'proposal' must be one of: " +
+        proposals.join(", ") +
+        ". More details: https://babeljs.io/docs/en/next/babel-plugin-proposal-pipeline-operator",
+    );
   }
 
   return {
diff --git a/packages/babel-preset-stage-0/src/index.js b/packages/babel-preset-stage-0/src/index.js
index b5034e4e6c..28d9dd33cc 100644
--- a/packages/babel-preset-stage-0/src/index.js
+++ b/packages/babel-preset-stage-0/src/index.js
@@ -2,6 +2,7 @@ import { declare } from "@babel/helper-plugin-utils";
 import presetStage1 from "@babel/preset-stage-1";
 
 import transformFunctionBind from "@babel/plugin-proposal-function-bind";
+import { proposals } from "@babel/plugin-proposal-pipeline-operator";
 
 export default declare((api, opts = {}) => {
   api.assertVersion(7);
@@ -38,8 +39,9 @@ export default declare((api, opts = {}) => {
   if (typeof pipelineProposal !== "string") {
     throw new Error(
       "The pipeline operator requires a proposal set." +
-        " You must pass the 'pipelineProposal' option to" +
-        " @babel/preset-stage-0",
+        " You must pass 'pipelineProposal' option to" +
+        " @babel/preset-stage-0 whose value must be one of: " +
+        proposals.join(", "),
     );
   }
 
diff --git a/packages/babel-preset-stage-1/src/index.js b/packages/babel-preset-stage-1/src/index.js
index 12d0c64de0..2c50a12fca 100644
--- a/packages/babel-preset-stage-1/src/index.js
+++ b/packages/babel-preset-stage-1/src/index.js
@@ -4,7 +4,9 @@ import presetStage2 from "@babel/preset-stage-2";
 import transformExportDefaultFrom from "@babel/plugin-proposal-export-default-from";
 import transformLogicalAssignmentOperators from "@babel/plugin-proposal-logical-assignment-operators";
 import transformOptionalChaining from "@babel/plugin-proposal-optional-chaining";
-import transformPipelineOperator from "@babel/plugin-proposal-pipeline-operator";
+import transformPipelineOperator, {
+  proposals,
+} from "@babel/plugin-proposal-pipeline-operator";
 import transformNullishCoalescingOperator from "@babel/plugin-proposal-nullish-coalescing-operator";
 import transformDoExpressions from "@babel/plugin-proposal-do-expressions";
 
@@ -44,7 +46,8 @@ export default declare((api, opts = {}) => {
     throw new Error(
       "The pipeline operator requires a proposal set." +
         " You must pass 'pipelineProposal' option to" +
-        " @babel/preset-stage-1",
+        " @babel/preset-stage-1 whose value must be one of: " +
+        proposals.join(", "),
     );
   }