Add proposal flag to pipeline plugin (#8196)

This is going to be required so we can add support for other proposals,
as well as later set the accepted proposal as the default.

Update stage-0 and stage-1 presets with `pipelineProposal` to thread down to
the plugin.

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/foobar/options.json

@@ -1,3 +1,6 @@
 {
-  "presets": [["stage-0", { "decoratorsLegacy": true }], "es2015"]
+  "presets": [
+    ["stage-0", { "decoratorsLegacy": true, "pipelineProposal": "minimal" }],
+    "es2015"
+  ]
 }

packages/babel-plugin-proposal-class-properties/test/fixtures/public-loose/foobar/options.json

@@ -1,7 +1,7 @@
 {
   "plugins": ["external-helpers", ["proposal-class-properties", {"loose": true}]],
   "presets": [
-    ["stage-0", { "decoratorsLegacy": true }],
+    ["stage-0", { "decoratorsLegacy": true, "pipelineProposal": "minimal" }],
     "es2015"
   ]
 }

packages/babel-plugin-proposal-class-properties/test/fixtures/public/foobar/options.json

@@ -1,7 +1,7 @@
 {
   "plugins": ["external-helpers", "proposal-class-properties"],
   "presets": [
-    ["stage-0", { "decoratorsLegacy": true }],
+    ["stage-0", { "decoratorsLegacy": true, "pipelineProposal": "minimal" }],
     "es2015"
   ]
 }

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-regression/7030/options.json

@@ -1,6 +1,6 @@
 {
   "presets": [
     "es2015",
-    ["stage-0", { "decoratorsLegacy": true }]
+    ["stage-0", { "decoratorsLegacy": true, "pipelineProposal": "minimal" }]
   ]
 }

packages/babel-plugin-proposal-pipeline-operator/test/fixtures/pipeline-operator/options.json

@@ -1,3 +1,5 @@
 {
-  "plugins": ["proposal-pipeline-operator"]
+  "plugins": [
+    ["proposal-pipeline-operator", { "proposal": "minimal" }]
+  ]
 }

packages/babel-plugin-syntax-pipeline-operator/src/index.js

@@ -1,11 +1,17 @@
 import { declare } from "@babel/helper-plugin-utils";
 
-export default declare(api => {
+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(", "));
+  }
+
   return {
     manipulateOptions(opts, parserOpts) {
-      parserOpts.plugins.push("pipelineOperator");
+      parserOpts.plugins.push(["pipelineOperator", { proposal }]);
     },
   };
 });

packages/babel-preset-stage-0/src/index.js

@@ -6,7 +6,12 @@ import transformFunctionBind from "@babel/plugin-proposal-function-bind";
 export default declare((api, opts = {}) => {
   api.assertVersion(7);
 
-  const { loose = false, useBuiltIns = false, decoratorsLegacy = false } = opts;
+  const {
+    loose = false,
+    useBuiltIns = false,
+    decoratorsLegacy = false,
+    pipelineProposal,
+  } = opts;
 
   if (typeof loose !== "boolean") {
     throw new Error("@babel/preset-stage-0 'loose' option must be a boolean.");
@@ -30,8 +35,21 @@ 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",
+    );
+  }
+
   return {
-    presets: [[presetStage1, { loose, useBuiltIns, decoratorsLegacy }]],
+    presets: [
+      [
+        presetStage1,
+        { loose, useBuiltIns, decoratorsLegacy, pipelineProposal },
+      ],
+    ],
     plugins: [transformFunctionBind],
   };
 });

packages/babel-preset-stage-1/src/index.js

@@ -11,7 +11,12 @@ import transformDoExpressions from "@babel/plugin-proposal-do-expressions";
 export default declare((api, opts = {}) => {
   api.assertVersion(7);
 
-  const { loose = false, useBuiltIns = false, decoratorsLegacy = false } = opts;
+  const {
+    loose = false,
+    useBuiltIns = false,
+    decoratorsLegacy = false,
+    pipelineProposal,
+  } = opts;
 
   if (typeof loose !== "boolean") {
     throw new Error("@babel/preset-stage-1 'loose' option must be a boolean.");
@@ -35,13 +40,21 @@ export default declare((api, opts = {}) => {
     );
   }
 
+  if (typeof pipelineProposal !== "string") {
+    throw new Error(
+      "The pipeline operator requires a proposal set." +
+        " You must pass 'pipelineProposal' option to" +
+        " @babel/preset-stage-1",
+    );
+  }
+
   return {
     presets: [[presetStage2, { loose, useBuiltIns, decoratorsLegacy }]],
     plugins: [
       transformExportDefaultFrom,
       transformLogicalAssignmentOperators,
       [transformOptionalChaining, { loose }],
-      transformPipelineOperator,
+      [transformPipelineOperator, { proposal: pipelineProposal }],
       [transformNullishCoalescingOperator, { loose }],
       transformDoExpressions,
     ],