diff --git a/packages/babylon/src/parser/expression.js b/packages/babylon/src/parser/expression.js
index e85f312f3e..38f52cde4a 100644
--- a/packages/babylon/src/parser/expression.js
+++ b/packages/babylon/src/parser/expression.js
@@ -236,8 +236,7 @@ pp.parseSubscripts = function(base, startPos, startLoc, noCalls) {
       this.expect(tt.bracketR);
       base = this.finishNode(node, "MemberExpression");
     } else if (!noCalls && this.state.type === tt.parenL) {
-      let possibleAsync = false;
-      if (base.type === "Identifier" && base.name === "async" && !this.canInsertSemicolon()) possibleAsync = true;
+      let possibleAsync = base.type === "Identifier" && base.name === "async" && !this.canInsertSemicolon();
       this.next();
 
       let node = this.startNodeAt(startPos, startLoc);
diff --git a/packages/babylon/src/parser/lval.js b/packages/babylon/src/parser/lval.js
index 7804cb83bf..68fd6c1252 100644
--- a/packages/babylon/src/parser/lval.js
+++ b/packages/babylon/src/parser/lval.js
@@ -100,20 +100,20 @@ pp.parseRest = function () {
 
 pp.parseBindingAtom = function () {
   switch (this.state.type) {
-  case tt.name:
-    return this.parseIdent();
+    case tt.name:
+      return this.parseIdent();
 
-  case tt.bracketL:
-    let node = this.startNode();
-    this.next();
-    node.elements = this.parseBindingList(tt.bracketR, true, true);
-    return this.finishNode(node, "ArrayPattern");
+    case tt.bracketL:
+      let node = this.startNode();
+      this.next();
+      node.elements = this.parseBindingList(tt.bracketR, true, true);
+      return this.finishNode(node, "ArrayPattern");
 
-  case tt.braceL:
-    return this.parseObj(true);
+    case tt.braceL:
+      return this.parseObj(true);
 
-  default:
-    this.unexpected();
+    default:
+      this.unexpected();
   }
 };
 
@@ -163,49 +163,45 @@ pp.parseMaybeDefault = function (startPos, startLoc, left) {
 
 pp.checkLVal = function (expr, isBinding, checkClashes) {
   switch (expr.type) {
-  case "Identifier":
-    if (this.strict && (reservedWords.strictBind(expr.name) || reservedWords.strict(expr.name)))
-      this.raise(expr.start, (isBinding ? "Binding " : "Assigning to ") + expr.name + " in strict mode");
-    if (checkClashes) {
-      if (checkClashes[expr.name]) {
-        this.raise(expr.start, "Argument name clash in strict mode");
-      } else {
-        checkClashes[expr.name] = true;
+    case "Identifier":
+      if (this.strict && (reservedWords.strictBind(expr.name) || reservedWords.strict(expr.name)))
+        this.raise(expr.start, (isBinding ? "Binding " : "Assigning to ") + expr.name + " in strict mode");
+      if (checkClashes) {
+        if (checkClashes[expr.name]) {
+          this.raise(expr.start, "Argument name clash in strict mode");
+        } else {
+          checkClashes[expr.name] = true;
+        }
       }
-    }
-    break;
+      break;
 
-  case "MemberExpression":
-    if (isBinding) this.raise(expr.start, (isBinding ? "Binding" : "Assigning to") + " member expression");
-    break;
+    case "MemberExpression":
+      if (isBinding) this.raise(expr.start, (isBinding ? "Binding" : "Assigning to") + " member expression");
+      break;
 
-  case "ObjectPattern":
-       for (let prop of (expr.properties: Array)) {
-      if (prop.type === "Property") prop = prop.value;
-      this.checkLVal(prop, isBinding, checkClashes);
-    }
-    break;
+    case "ObjectPattern":
+         for (let prop of (expr.properties: Array)) {
+        if (prop.type === "Property") prop = prop.value;
+        this.checkLVal(prop, isBinding, checkClashes);
+      }
+      break;
 
-  case "ArrayPattern":
-    for (let elem of (expr.elements: Array)) {
-      if (elem) this.checkLVal(elem, isBinding, checkClashes);
-    }
-    break;
+    case "ArrayPattern":
+      for (let elem of (expr.elements: Array)) {
+        if (elem) this.checkLVal(elem, isBinding, checkClashes);
+      }
+      break;
 
-  case "AssignmentPattern":
-    this.checkLVal(expr.left, isBinding, checkClashes);
-    break;
+    case "AssignmentPattern":
+      this.checkLVal(expr.left, isBinding, checkClashes);
+      break;
 
-  case "SpreadProperty":
-  case "RestElement":
-    this.checkLVal(expr.argument, isBinding, checkClashes);
-    break;
+    case "SpreadProperty":
+    case "RestElement":
+      this.checkLVal(expr.argument, isBinding, checkClashes);
+      break;
 
-  case "ParenthesizedExpression":
-    this.checkLVal(expr.expression, isBinding, checkClashes);
-    break;
-
-  default:
-    this.raise(expr.start, (isBinding ? "Binding" : "Assigning to") + " rvalue");
+    default:
+      this.raise(expr.start, (isBinding ? "Binding" : "Assigning to") + " rvalue");
   }
 };
diff --git a/packages/babylon/src/parser/node.js b/packages/babylon/src/parser/node.js
index ef378d1711..7fb0cd2a62 100644
--- a/packages/babylon/src/parser/node.js
+++ b/packages/babylon/src/parser/node.js
@@ -10,10 +10,7 @@ export class Node {
     this.type = "";
     this.start = pos;
     this.end = 0;
-
-    if (parser) {
-      this.loc = new SourceLocation(loc);
-    }
+    this.loc = new SourceLocation(loc);
   }
 
   __clone() {
diff --git a/packages/babylon/src/plugins/jsx/index.js b/packages/babylon/src/plugins/jsx/index.js
index 81fcd6c9f6..b07e60fe3b 100644
--- a/packages/babylon/src/plugins/jsx/index.js
+++ b/packages/babylon/src/plugins/jsx/index.js
@@ -121,7 +121,6 @@ pp.jsxReadString = function(quote) {
 pp.jsxReadEntity = function() {
   var str = "", count = 0, entity;
   var ch = this.input[this.state.pos];
-  if (ch !== "&") this.raise(this.state.pos, "Entity must start with an ampersand");
 
   var startPos = ++this.state.pos;
   while (this.state.pos < this.input.length && count++ < 10) {
diff --git a/packages/babylon/src/tokenizer/index.js b/packages/babylon/src/tokenizer/index.js
index 5c33f02f43..5d2a210f4e 100644
--- a/packages/babylon/src/tokenizer/index.js
+++ b/packages/babylon/src/tokenizer/index.js
@@ -79,11 +79,6 @@ export default class Tokenizer {
     return curr;
   }
 
-  getToken() {
-    this.next();
-    return new Token(this.state);
-  }
-
   // Toggle strict mode. Re-reads the next number or string to please
   // pedantic tests (`"use strict"; 010;` should fail).
 
@@ -455,13 +450,19 @@ export default class Tokenizer {
     for (;;) {
       if (this.state.pos >= this.input.length) this.raise(start, "Unterminated regular expression");
       let ch = this.input.charAt(this.state.pos);
-      if (lineBreak.test(ch)) this.raise(start, "Unterminated regular expression");
+      if (lineBreak.test(ch)) {
+        this.raise(start, "Unterminated regular expression");
+      }
       if (escaped) {
         escaped = false;
       } else {
-        if (ch === "[") inClass = true;
-        else if (ch === "]" && inClass) inClass = false;
-        else if (ch === "/" && !inClass) break;
+        if (ch === "[") {
+          inClass = true;
+        } else if (ch === "]" && inClass) {
+          inClass = false;
+        } else if (ch === "/" && !inClass) {
+          break;
+        }
         escaped = ch === "\\";
       }
       ++this.state.pos;
@@ -502,7 +503,11 @@ export default class Tokenizer {
       // case the current environment doesn't support the flags it uses.
       value = tryCreateRegexp.call(this, content, mods);
     }
-    return this.finishToken(tt.regexp, {pattern: content, flags: mods, value: value});
+    return this.finishToken(tt.regexp, {
+      pattern: content,
+      flags: mods,
+      value
+    });
   }
 
   // Read an integer in the given radix. Return null if zero digits
diff --git a/packages/babylon/src/util/identifier.js b/packages/babylon/src/util/identifier.js
index 3bfe47cb36..48847c6277 100644
--- a/packages/babylon/src/util/identifier.js
+++ b/packages/babylon/src/util/identifier.js
@@ -83,19 +83,18 @@ function isInAstralSet(code, set) {
 
 // Test whether a given character code starts an identifier.
 
-export function isIdentifierStart(code, astral) {
+export function isIdentifierStart(code) {
   if (code < 65) return code === 36;
   if (code < 91) return true;
   if (code < 97) return code === 95;
   if (code < 123) return true;
   if (code <= 0xffff) return code >= 0xaa && nonASCIIidentifierStart.test(String.fromCharCode(code));
-  if (astral === false) return false;
   return isInAstralSet(code, astralIdentifierStartCodes);
 }
 
 // Test whether a given character is part of an identifier.
 
-export function isIdentifierChar(code, astral) {
+export function isIdentifierChar(code) {
   if (code < 48) return code === 36;
   if (code < 58) return true;
   if (code < 65) return false;
@@ -103,6 +102,5 @@ export function isIdentifierChar(code, astral) {
   if (code < 97) return code === 95;
   if (code < 123) return true;
   if (code <= 0xffff) return code >= 0xaa && nonASCIIidentifier.test(String.fromCharCode(code));
-  if (astral === false) return false;
   return isInAstralSet(code, astralIdentifierStartCodes) || isInAstralSet(code, astralIdentifierCodes);
 }
diff --git a/packages/babylon/src/util/location.js b/packages/babylon/src/util/location.js
index 6130950b15..883d4b3daa 100644
--- a/packages/babylon/src/util/location.js
+++ b/packages/babylon/src/util/location.js
@@ -8,10 +8,6 @@ export class Position {
     this.line = line;
     this.column = col;
   }
-
-  offset(n) {
-    return new Position(this.line, this.column + n);
-  }
 }
 
 export class SourceLocation {
diff --git a/packages/babylon/test/fixtures/flow/declare-statements/invalid/actual.js b/packages/babylon/test/fixtures/flow/declare-statements/invalid/actual.js
new file mode 100644
index 0000000000..c60ac0ee7d
--- /dev/null
+++ b/packages/babylon/test/fixtures/flow/declare-statements/invalid/actual.js
@@ -0,0 +1 @@
+declare foobar
diff --git a/packages/babylon/test/fixtures/flow/declare-statements/invalid/options.json b/packages/babylon/test/fixtures/flow/declare-statements/invalid/options.json
new file mode 100644
index 0000000000..9ce9658f7d
--- /dev/null
+++ b/packages/babylon/test/fixtures/flow/declare-statements/invalid/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (1:8)"
+}
diff --git a/packages/babylon/test/fixtures/harmony/computed-properties/call-expression/actual.js b/packages/babylon/test/fixtures/harmony/computed-properties/call-expression/actual.js
new file mode 100644
index 0000000000..15b577cc19
--- /dev/null
+++ b/packages/babylon/test/fixtures/harmony/computed-properties/call-expression/actual.js
@@ -0,0 +1,3 @@
+var foo = {
+  [bar()]: ""
+};
diff --git a/packages/babylon/test/fixtures/harmony/computed-properties/call-expression/expected.json b/packages/babylon/test/fixtures/harmony/computed-properties/call-expression/expected.json
new file mode 100644
index 0000000000..df5fedc3b7
--- /dev/null
+++ b/packages/babylon/test/fixtures/harmony/computed-properties/call-expression/expected.json
@@ -0,0 +1,169 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 28,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 3,
+      "column": 2
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 28,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 3,
+        "column": 2
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "VariableDeclaration",
+        "start": 0,
+        "end": 28,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 2
+          }
+        },
+        "declarations": [
+          {
+            "type": "VariableDeclarator",
+            "start": 4,
+            "end": 27,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 4
+              },
+              "end": {
+                "line": 3,
+                "column": 1
+              }
+            },
+            "id": {
+              "type": "Identifier",
+              "start": 4,
+              "end": 7,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 4
+                },
+                "end": {
+                  "line": 1,
+                  "column": 7
+                }
+              },
+              "name": "foo"
+            },
+            "init": {
+              "type": "ObjectExpression",
+              "start": 10,
+              "end": 27,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 10
+                },
+                "end": {
+                  "line": 3,
+                  "column": 1
+                }
+              },
+              "properties": [
+                {
+                  "type": "Property",
+                  "start": 14,
+                  "end": 25,
+                  "loc": {
+                    "start": {
+                      "line": 2,
+                      "column": 2
+                    },
+                    "end": {
+                      "line": 2,
+                      "column": 13
+                    }
+                  },
+                  "method": false,
+                  "shorthand": false,
+                  "computed": true,
+                  "key": {
+                    "type": "CallExpression",
+                    "start": 15,
+                    "end": 20,
+                    "loc": {
+                      "start": {
+                        "line": 2,
+                        "column": 3
+                      },
+                      "end": {
+                        "line": 2,
+                        "column": 8
+                      }
+                    },
+                    "callee": {
+                      "type": "Identifier",
+                      "start": 15,
+                      "end": 18,
+                      "loc": {
+                        "start": {
+                          "line": 2,
+                          "column": 3
+                        },
+                        "end": {
+                          "line": 2,
+                          "column": 6
+                        }
+                      },
+                      "name": "bar"
+                    },
+                    "arguments": []
+                  },
+                  "value": {
+                    "type": "Literal",
+                    "start": 23,
+                    "end": 25,
+                    "loc": {
+                      "start": {
+                        "line": 2,
+                        "column": 11
+                      },
+                      "end": {
+                        "line": 2,
+                        "column": 13
+                      }
+                    },
+                    "value": "",
+                    "rawValue": "",
+                    "raw": "\"\""
+                  },
+                  "kind": "init"
+                }
+              ]
+            }
+          }
+        ],
+        "kind": "var"
+      }
+    ]
+  },
+  "comments": []
+}
\ No newline at end of file
diff --git a/packages/babylon/test/fixtures/jsx/errors/attribute-arbitrary-expression/actual.js b/packages/babylon/test/fixtures/jsx/errors/attribute-arbitrary-expression/actual.js
new file mode 100644
index 0000000000..d0fa2bd1b7
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/attribute-arbitrary-expression/actual.js
@@ -0,0 +1 @@
+<Foo bar=bar() />
diff --git a/packages/babylon/test/fixtures/jsx/errors/attribute-arbitrary-expression/options.json b/packages/babylon/test/fixtures/jsx/errors/attribute-arbitrary-expression/options.json
new file mode 100644
index 0000000000..19a214000f
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/attribute-arbitrary-expression/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "JSX value should be either an expression or a quoted JSX text (1:9)"
+}
diff --git a/packages/babylon/test/fixtures/jsx/errors/attribute-empty-expression/actual.js b/packages/babylon/test/fixtures/jsx/errors/attribute-empty-expression/actual.js
new file mode 100644
index 0000000000..a6aa94b0a8
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/attribute-empty-expression/actual.js
@@ -0,0 +1 @@
+<foo bar={} />
diff --git a/packages/babylon/test/fixtures/jsx/errors/attribute-empty-expression/options.json b/packages/babylon/test/fixtures/jsx/errors/attribute-empty-expression/options.json
new file mode 100644
index 0000000000..d5960e11a3
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/attribute-empty-expression/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "JSX attributes must only be assigned a non-empty expression (1:9)"
+}
diff --git a/packages/babylon/test/fixtures/jsx/errors/unclosed-tag/actual.js b/packages/babylon/test/fixtures/jsx/errors/unclosed-tag/actual.js
new file mode 100644
index 0000000000..1fee584ee3
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/unclosed-tag/actual.js
@@ -0,0 +1 @@
+<foo>yes
diff --git a/packages/babylon/test/fixtures/jsx/errors/unclosed-tag/options.json b/packages/babylon/test/fixtures/jsx/errors/unclosed-tag/options.json
new file mode 100644
index 0000000000..4b723200df
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/unclosed-tag/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "Unterminated JSX contents (1:5)"
+}
diff --git a/packages/babylon/test/fixtures/jsx/errors/unterminated-string/actual.js b/packages/babylon/test/fixtures/jsx/errors/unterminated-string/actual.js
new file mode 100644
index 0000000000..32fb36baa5
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/unterminated-string/actual.js
@@ -0,0 +1 @@
+<foo bar="
diff --git a/packages/babylon/test/fixtures/jsx/errors/unterminated-string/options.json b/packages/babylon/test/fixtures/jsx/errors/unterminated-string/options.json
new file mode 100644
index 0000000000..78911055bc
--- /dev/null
+++ b/packages/babylon/test/fixtures/jsx/errors/unterminated-string/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "Unterminated string constant (1:9)"
+}
diff --git a/packages/babylon/test/index.js b/packages/babylon/test/index.js
index a50bf4b3ab..593793cd5f 100644
--- a/packages/babylon/test/index.js
+++ b/packages/babylon/test/index.js
@@ -18,6 +18,12 @@ _.each(fixtures, function (suites, name) {
   });
 });
 
+function save(test, ast) {
+  delete ast.tokens;
+  if (!ast.comments.length) delete ast.comments;
+  require("fs").writeFileSync(test.expect.loc, JSON.stringify(ast, null, "  "));
+}
+
 function runTest(test) {
   var opts = test.options;
   opts.locations = true;
@@ -38,18 +44,21 @@ function runTest(test) {
     throw err;
   }
 
+  if (!test.expect.code) {
+    test.expect.loc += "on";
+    return save(test, ast);
+  }
+
   if (opts.throws) {
     throw new Error("Expected error message: " + opts.throws + ". But parsing succeeded.");
   } else {
     try {
       var mis = misMatch(JSON.parse(test.expect.code), ast);
     } catch (err) {
-      console.log(test.expect.code);
+      // save(test, ast);
       throw err;
     }
     if (mis) {
-      //delete ast.tokens;
-      //require("fs").writeFileSync(test.expect.loc, JSON.stringify(ast, null, "  "));
       throw new Error(mis);
     }
   }