Enable solo await in F# pipelines

babel · Feb 24, 2019 · b08f341 · b08f341
1 parent da3515c
commit b08f341
Show file tree

Hide file tree

Showing 5 changed files with 207 additions and 2 deletions.
diff --git a/packages/babel-parser/src/parser/expression.js b/packages/babel-parser/src/parser/expression.js
@@ -410,7 +410,9 @@ export default class ExpressionParser extends LValParser {
               );
             });
           case "fsharp":
-            return this.parseFSharpPipelineBody(op, prec, noIn);
+            return this.withSoloAwaitPermittingContext(() => {
+              return this.parseFSharpPipelineBody(op, prec, noIn);
+            });
         }
       // falls through
 
@@ -2074,7 +2076,9 @@ export default class ExpressionParser extends LValParser {
       );
     }
 
-    node.argument = this.parseMaybeUnary();
+    if (!this.state.soloAwait) {
+      node.argument = this.parseMaybeUnary();
+    }
     return this.finishNode(node, "AwaitExpression");
   }
 
@@ -2264,6 +2268,17 @@ export default class ExpressionParser extends LValParser {
     }
   }
 
+  withSoloAwaitPermittingContext<T>(callback: () => T): T {
+    const outerContextSoloAwaitState = this.state.soloAwait;
+    this.state.soloAwait = true;
+
+    try {
+      return callback();
+    } finally {
+      this.state.soloAwait = outerContextSoloAwaitState;
+    }
+  }
+
   // Register the use of a primary topic reference (`#`) within the current
   // topic context.
   registerTopicReference(): void {

diff --git a/packages/babel-parser/src/tokenizer/state.js b/packages/babel-parser/src/tokenizer/state.js
@@ -87,6 +87,9 @@ export default class State {
     maxTopicIndex: null,
   };
 
+  // For the F# plugin
+  soloAwait: boolean = false;
+
   // Check whether we are in a (nested) class or not.
   classLevel: number = 0;
 

diff --git a/.../babel-parser/test/fixtures/experimental/pipeline-operator/proposal-fsharp-await/input.js b/.../babel-parser/test/fixtures/experimental/pipeline-operator/proposal-fsharp-await/input.js
@@ -0,0 +1,3 @@
+async function f () {
+  return x |> await;
+}
diff --git a/...el-parser/test/fixtures/experimental/pipeline-operator/proposal-fsharp-await/options.json b/...el-parser/test/fixtures/experimental/pipeline-operator/proposal-fsharp-await/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": [["pipelineOperator", { "proposal": "fsharp" }]]
+}
diff --git a/...bel-parser/test/fixtures/experimental/pipeline-operator/proposal-fsharp-await/output.json b/...bel-parser/test/fixtures/experimental/pipeline-operator/proposal-fsharp-await/output.json
@@ -0,0 +1,181 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 44,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 3,
+      "column": 1
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 44,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 3,
+        "column": 1
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "FunctionDeclaration",
+        "start": 0,
+        "end": 44,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 1
+          }
+        },
+        "id": {
+          "type": "Identifier",
+          "start": 15,
+          "end": 16,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 15
+            },
+            "end": {
+              "line": 1,
+              "column": 16
+            },
+            "identifierName": "f"
+          },
+          "name": "f"
+        },
+        "generator": false,
+        "async": true,
+        "params": [],
+        "body": {
+          "type": "BlockStatement",
+          "start": 20,
+          "end": 44,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 20
+            },
+            "end": {
+              "line": 3,
+              "column": 1
+            }
+          },
+          "body": [
+            {
+              "type": "ReturnStatement",
+              "start": 24,
+              "end": 42,
+              "loc": {
+                "start": {
+                  "line": 2,
+                  "column": 2
+                },
+                "end": {
+                  "line": 2,
+                  "column": 20
+                }
+              },
+              "argument": {
+                "type": "BinaryExpression",
+                "start": 31,
+                "end": 41,
+                "loc": {
+                  "start": {
+                    "line": 2,
+                    "column": 9
+                  },
+                  "end": {
+                    "line": 2,
+                    "column": 19
+                  }
+                },
+                "left": {
+                  "type": "PipelineHead",
+                  "start": 33,
+                  "end": 32,
+                  "loc": {
+                    "start": {
+                      "line": 2,
+                      "column": 11
+                    },
+                    "end": {
+                      "line": 2,
+                      "column": 10
+                    }
+                  },
+                  "head": {
+                    "type": "Identifier",
+                    "start": 31,
+                    "end": 32,
+                    "loc": {
+                      "start": {
+                        "line": 2,
+                        "column": 9
+                      },
+                      "end": {
+                        "line": 2,
+                        "column": 10
+                      },
+                      "identifierName": "x"
+                    },
+                    "name": "x"
+                  }
+                },
+                "operator": "|>",
+                "right": {
+                  "type": "PipelineBody",
+                  "start": 36,
+                  "end": 41,
+                  "loc": {
+                    "start": {
+                      "line": 2,
+                      "column": 14
+                    },
+                    "end": {
+                      "line": 2,
+                      "column": 19
+                    }
+                  },
+                  "body": {
+                    "type": "AwaitExpression",
+                    "start": 36,
+                    "end": 41,
+                    "loc": {
+                      "start": {
+                        "line": 2,
+                        "column": 14
+                      },
+                      "end": {
+                        "line": 2,
+                        "column": 19
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          ],
+          "directives": []
+        }
+      }
+    ],
+    "directives": []
+  }
+}