Converge with Babel re optional chaining

- Eliminate `SafeMemberExpression` node type; use `MemberExpression` with `optional = true` instead. - Use `optional = true` for safe `CallExpression`s - Allow proposed `x?.(arg, arg…)` syntax for safe calls
wcjohnson · Sep 23, 2017 · 926a863 · 926a863
1 parent 99f8c0b
commit 926a863
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Showing 18 changed files with 169 additions and 50 deletions.
diff --git a/src/parser/expression.js b/src/parser/expression.js
@@ -426,28 +426,39 @@ pp.parseSubscripts = function (base, startPos, startLoc, noCalls) {
       if (this.hasPlugin("enforceSubscriptIndentation") && this.isNonIndentedBreakFrom(startPos)) {
         this.unexpected(null, "Indentation required.");
       }
-      // `x?.y`
-      const node = this.startNodeAt(startPos, startLoc);
+
       const op = this.state.value;
       this.next();
-      node.object = base;
-      if (op === "?.") {
-        // arr?.0 -> arr?[0]
-        if (this.match(tt.num)) {
-          node.property = this.parseLiteral(this.state.value, "NumericLiteral");
+
+      if (op === "?." && this.match(tt.parenL) && this.hasPlugin("safeCallExpression")) {
+        // x?.(...) = JS safe call proposal
+        const [next, canSubscript] = this.parseSafeCall(base, startPos, startLoc);
+        if (canSubscript) base = next; else return base;
+      } else {
+        // `x?.y` `x?[y]`
+        const node = this.startNodeAt(startPos, startLoc);
+        node.object = base;
+
+        if (op === "?.") {
+          if (this.match(tt.num)) {
+            // arr?.0 -> arr?[0]
+            node.property = this.parseLiteral(this.state.value, "NumericLiteral");
+            node.computed = true;
+          } else {
+            node.property = this.parseIdentifierOrPlaceholder(true);
+            node.computed = false;
+          }
+        } else if (op === "?[") {
+          node.property = this.parseExpression();
           node.computed = true;
+          this.expect(tt.bracketR);
         } else {
-          node.property = this.parseIdentifierOrPlaceholder(true);
-          node.computed = false;
+          this.unexpected();
         }
-      } else if (op === "?[") {
-        node.property = this.parseExpression();
-        node.computed = true;
-        this.expect(tt.bracketR);
-      } else {
-        this.unexpected();
+
+        node.optional = true;
+        base = this.finishNode(node, "MemberExpression");
       }
-      base = this.finishNode(node, "SafeMemberExpression");
     } else if (
       (this.hasPlugin("safeCallExpression") || this.hasPlugin("existentialExpression")) &&
       this.match(tt.question) &&

diff --git a/src/plugins/safeCallExistential.js b/src/plugins/safeCallExistential.js
@@ -10,7 +10,7 @@ export default function(parser) {
   pp.parseSafeCall = function(expr, startPos, startLoc) {
     const node = this.startNodeAt(startPos, startLoc);
     node.callee = expr;
-    node.safe = true;
+    node.optional = true;
 
     if (this.hasPlugin("bangCall") && this.isBang()) {
       const canSubscript = this.parseBangCall(node, "CallExpression");

diff --git a/src/plugins/tildeCall.js b/src/plugins/tildeCall.js
@@ -18,7 +18,7 @@ export default function(parser) {
 
     // Allow safe tilde calls (a~b?(c))
     if (this.hasPlugin("safeCallExpression") && this.eat(tt.question)) {
-      node.safe = true;
+      node.optional = true;
     }
 
     // Allow bang tilde calls

diff --git a/test/fixtures/bang-call/safe/basic/expected.json b/test/fixtures/bang-call/safe/basic/expected.json
@@ -73,7 +73,7 @@
             },
             "name": "a"
           },
-          "safe": true,
+          "optional": true,
           "arguments": [
             {
               "type": "Identifier",

diff --git a/test/fixtures/lightscript/safe-member-expression/basic/expected.json b/test/fixtures/lightscript/safe-member-expression/basic/expected.json
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "SafeMemberExpression",
+          "type": "MemberExpression",
           "start": 0,
           "end": 4,
           "loc": {
@@ -90,7 +90,8 @@
             },
             "name": "y"
           },
-          "computed": false
+          "computed": false,
+          "optional": true
         }
       }
     ],

diff --git a/test/fixtures/lightscript/safe-member-expression/chained/expected.json b/test/fixtures/lightscript/safe-member-expression/chained/expected.json
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "SafeMemberExpression",
+          "type": "MemberExpression",
           "start": 0,
           "end": 26,
           "loc": {
@@ -113,7 +113,7 @@
                     }
                   },
                   "object": {
-                    "type": "SafeMemberExpression",
+                    "type": "MemberExpression",
                     "start": 0,
                     "end": 9,
                     "loc": {
@@ -127,7 +127,7 @@
                       }
                     },
                     "object": {
-                      "type": "SafeMemberExpression",
+                      "type": "MemberExpression",
                       "start": 0,
                       "end": 6,
                       "loc": {
@@ -207,7 +207,8 @@
                         },
                         "name": "a"
                       },
-                      "computed": false
+                      "computed": false,
+                      "optional": true
                     },
                     "property": {
                       "type": "Identifier",
@@ -226,7 +227,8 @@
                       },
                       "name": "b"
                     },
-                    "computed": false
+                    "computed": false,
+                    "optional": true
                   },
                   "property": {
                     "type": "Identifier",
@@ -339,7 +341,8 @@
             },
             "name": "h"
           },
-          "computed": false
+          "computed": false,
+          "optional": true
         }
       }
     ],

diff --git a/test/fixtures/lightscript/safe-member-expression/computed/expected.json b/test/fixtures/lightscript/safe-member-expression/computed/expected.json
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "SafeMemberExpression",
+          "type": "MemberExpression",
           "start": 0,
           "end": 9,
           "loc": {
@@ -123,7 +123,8 @@
               "name": "y"
             }
           },
-          "computed": true
+          "computed": true,
+          "optional": true
         }
       }
     ],

diff --git a/test/fixtures/lightscript/safe-member-expression/index/expected.json b/test/fixtures/lightscript/safe-member-expression/index/expected.json
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "SafeMemberExpression",
+          "type": "MemberExpression",
           "start": 0,
           "end": 4,
           "loc": {
@@ -87,16 +87,17 @@
                 "column": 4
               }
             },
-            "value": 0,
             "extra": {
-              "raw": "0",
-              "rawValue": 0
-            }
+              "rawValue": 0,
+              "raw": "0"
+            },
+            "value": 0
           },
-          "computed": true
+          "computed": true,
+          "optional": true
         }
       }
     ],
     "directives": []
   }
-}
+}
diff --git a/test/fixtures/safe-call-expression/js/basic/actual.js b/test/fixtures/safe-call-expression/js/basic/actual.js
@@ -0,0 +1 @@
+f?.(x)
diff --git a/test/fixtures/safe-call-expression/js/basic/expected.json b/test/fixtures/safe-call-expression/js/basic/expected.json
@@ -0,0 +1,101 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 6,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 6
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 6,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 6
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 6,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 6
+          }
+        },
+        "expression": {
+          "type": "CallExpression",
+          "start": 0,
+          "end": 6,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 6
+            }
+          },
+          "callee": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 0
+              },
+              "end": {
+                "line": 1,
+                "column": 1
+              },
+              "identifierName": "f"
+            },
+            "name": "f"
+          },
+          "optional": true,
+          "arguments": [
+            {
+              "type": "Identifier",
+              "start": 4,
+              "end": 5,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 4
+                },
+                "end": {
+                  "line": 1,
+                  "column": 5
+                },
+                "identifierName": "x"
+              },
+              "name": "x"
+            }
+          ]
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/test/fixtures/safe-call-expression/lightscript/basic/expected.json b/test/fixtures/safe-call-expression/lightscript/basic/expected.json
@@ -73,6 +73,7 @@
             },
             "name": "f"
           },
+          "optional": true,
           "arguments": [
             {
               "type": "Identifier",
@@ -91,8 +92,7 @@
               },
               "name": "x"
             }
-          ],
-          "safe": true
+          ]
         }
       }
     ],

diff --git a/test/fixtures/safe-call-expression/lightscript/chained/expected.json b/test/fixtures/safe-call-expression/lightscript/chained/expected.json
@@ -87,11 +87,11 @@
               },
               "name": "f"
             },
-            "arguments": [],
-            "safe": true
+            "optional": true,
+            "arguments": []
           },
-          "arguments": [],
-          "safe": true
+          "optional": true,
+          "arguments": []
         }
       }
     ],

diff --git a/test/fixtures/safe-call-expression/lightscript/match-test/expected.json b/test/fixtures/safe-call-expression/lightscript/match-test/expected.json
@@ -106,7 +106,7 @@
                   },
                   "name": "it"
                 },
-                "safe": true,
+                "optional": true,
                 "arguments": []
               }
             ],

diff --git a/test/fixtures/safe-call-expression/lightscript/match-typecast-unfortunate/expected.json b/test/fixtures/safe-call-expression/lightscript/match-typecast-unfortunate/expected.json
@@ -120,7 +120,7 @@
                     },
                     "name": "it"
                   },
-                  "safe": true,
+                  "optional": true,
                   "arguments": [
                     {
                       "type": "Identifier",

diff --git a/test/fixtures/safe-call-expression/lightscript/ternary-3/expected.json b/test/fixtures/safe-call-expression/lightscript/ternary-3/expected.json
@@ -121,6 +121,7 @@
               },
               "name": "c"
             },
+            "optional": true,
             "arguments": [
               {
                 "type": "Identifier",
@@ -139,8 +140,7 @@
                 },
                 "name": "d"
               }
-            ],
-            "safe": true
+            ]
           }
         }
       }