Reuse hash token instead of new primaryTopicToken

Set whether we're in a pipeline in order to determine how to parse the
hash. The error message changes as a result, since the `hash` never
enters the block.

packages/babel-parser/src/parser/expression.js

@@ -298,6 +298,7 @@ export default class ExpressionParser extends LValParser {
         const op = this.state.type;
 
         if (op === tt.pipeline) {
+          this.state.inPipeline = true;
           this.checkPipelineAtInfixOperator(left, leftStartPos);
         } else if (op === tt.nullishCoalescing) {
           this.expectPlugin("nullishCoalescingOperator");
@@ -931,26 +932,30 @@ export default class ExpressionParser extends LValParser {
         }
       }
 
-      case tt.primaryTopicReference: {
-        this.expectPlugin("pipelineOperator");
-        node = this.startNode();
+      case tt.hash: {
+        if (this.state.inPipeline) {
+          this.expectPlugin("pipelineOperator");
+          node = this.startNode();
 
-        if ("smart" !== this.getPluginOption("pipelineOperator", "proposal")) {
-          this.raise(
-            node.start,
-            "Primary Topic Reference found but pipelineOperator not passed 'smart' for 'proposal' option.",
-          );
-        }
+          if (
+            "smart" !== this.getPluginOption("pipelineOperator", "proposal")
+          ) {
+            this.raise(
+              node.start,
+              "Primary Topic Reference found but pipelineOperator not passed 'smart' for 'proposal' option.",
+            );
+          }
 
-        this.next();
-        if (this.primaryTopicReferenceIsAllowedInCurrentTopicContext()) {
-          this.registerTopicReference();
-          return this.finishNode(node, "PrimaryTopicReference");
-        } else {
-          throw this.raise(
-            node.start,
-            `Topic reference was used in a lexical context without topic binding`,
-          );
+          this.next();
+          if (this.primaryTopicReferenceIsAllowedInCurrentTopicContext()) {
+            this.registerTopicReference();
+            return this.finishNode(node, "PrimaryTopicReference");
+          } else {
+            throw this.raise(
+              node.start,
+              `Topic reference was used in a lexical context without topic binding`,
+            );
+          }
         }
       }
 

packages/babel-parser/src/tokenizer/index.js

@@ -431,7 +431,7 @@ export default class Tokenizer extends LocationParser {
           )}'`,
         );
       } else {
-        this.finishOp(tt.primaryTopicReference, 1);
+        this.finishOp(tt.hash, 1);
       }
     } else {
       this.raise(

packages/babel-parser/src/tokenizer/state.js

@@ -26,6 +26,7 @@ export default class State {
     this.maybeInArrowParameters = false;
     this.inGenerator = false;
     this.inAsync = false;
+    this.inPipeline = false;
     this.inPropertyName = false;
     this.inType = false;
     this.inClassProperty = false;
@@ -110,6 +111,7 @@ export default class State {
   inGenerator: boolean;
   inMethod: boolean | N.MethodKind;
   inAsync: boolean;
+  inPipeline: boolean;
   inType: boolean;
   noAnonFunctionType: boolean;
   inPropertyName: boolean;

packages/babel-parser/src/tokenizer/types.js

@@ -86,7 +86,6 @@ export const types: { [name: string]: TokenType } = {
   regexp: new TokenType("regexp", { startsExpr }),
   string: new TokenType("string", { startsExpr }),
   name: new TokenType("name", { startsExpr }),
-  primaryTopicReference: new TokenType("#", { startsExpr }),
   eof: new TokenType("eof"),
 
   // Punctuation token types.

packages/babel-parser/test/fixtures/experimental/pipeline-operator/proposal-smart-error,-unbound-topic,-simple/options.json

@@ -1,4 +1,4 @@
 {
   "plugins": [["pipelineOperator", { "proposal": "smart" }]],
-  "throws": "Topic reference was used in a lexical context without topic binding (1:4)"
+  "throws": "Unexpected token (1:4)"
 }