Update number lexer

Ensures graphql-js matches spec after graphql/graphql-spec#56

Adds tests for changed error and success cases, fixing #68

Author: leebyron

src/language/__tests__/lexer.js

@@ -256,6 +256,42 @@ describe('Lexer', () => {
       value: '0.123'
     });
 
+    expect(
+      lexOne('123e4')
+    ).to.deep.equal({
+      kind: TokenKind.FLOAT,
+      start: 0,
+      end: 5,
+      value: '123e4'
+    });
+
+    expect(
+      lexOne('123E4')
+    ).to.deep.equal({
+      kind: TokenKind.FLOAT,
+      start: 0,
+      end: 5,
+      value: '123E4'
+    });
+
+    expect(
+      lexOne('123e-4')
+    ).to.deep.equal({
+      kind: TokenKind.FLOAT,
+      start: 0,
+      end: 6,
+      value: '123e-4'
+    });
+
+    expect(
+      lexOne('123e+4')
+    ).to.deep.equal({
+      kind: TokenKind.FLOAT,
+      start: 0,
+      end: 6,
+      value: '123e+4'
+    });
+
     expect(
       lexOne('-1.123e4')
     ).to.deep.equal({
@@ -265,6 +301,15 @@ describe('Lexer', () => {
       value: '-1.123e4'
     });
 
+    expect(
+      lexOne('-1.123E4')
+    ).to.deep.equal({
+      kind: TokenKind.FLOAT,
+      start: 0,
+      end: 8,
+      value: '-1.123E4'
+    });
+
     expect(
       lexOne('-1.123e-4')
     ).to.deep.equal({
@@ -274,6 +319,15 @@ describe('Lexer', () => {
       value: '-1.123e-4'
     });
 
+    expect(
+      lexOne('-1.123e+4')
+    ).to.deep.equal({
+      kind: TokenKind.FLOAT,
+      start: 0,
+      end: 9,
+      value: '-1.123e+4'
+    });
+
     expect(
       lexOne('-1.123e4567')
     ).to.deep.equal({
@@ -295,6 +349,10 @@ describe('Lexer', () => {
       lexErr('1.')
     ).to.throw('Syntax Error GraphQL (1:3) Invalid number');
 
+    expect(
+      lexErr('.123')
+    ).to.throw('Syntax Error GraphQL (1:1) Unexpected character "."');
+
     expect(
       lexErr('1.A')
     ).to.throw('Syntax Error GraphQL (1:3) Invalid number');
@@ -303,10 +361,6 @@ describe('Lexer', () => {
       lexErr('-A')
     ).to.throw('Syntax Error GraphQL (1:2) Invalid number');
 
-    expect(
-      lexErr('1.0e+4')
-    ).to.throw('Syntax Error GraphQL (1:5) Invalid number');
-
     expect(
       lexErr('1.0e')
     ).to.throw('Syntax Error GraphQL (1:5) Invalid number');

src/language/lexer.js

@@ -247,7 +247,7 @@ function positionAfterWhitespace(body: string, startPosition: number): number {
  * or an int depending on whether a decimal point appears.
  *
  * Int:   -?(0|[1-9][0-9]*)
- * Float: -?(0|[1-9][0-9]*)\.[0-9]+(e-?[0-9]+)?
+ * Float: -?(0|[1-9][0-9]*)(\.[0-9]+)?((E|e)(+|-)?[0-9]+)?
  */
 function readNumber(source, start, firstCode) {
   var code = firstCode;
@@ -280,19 +280,21 @@ function readNumber(source, start, firstCode) {
     } else {
       throw syntaxError(source, position, 'Invalid number.');
     }
+  }
+
+  if (code === 69 || code === 101) { // E e
+    isFloat = true;
 
-    if (code === 101) { // e
+    code = charCodeAt.call(body, ++position);
+    if (code === 43 || code === 45) { // + -
       code = charCodeAt.call(body, ++position);
-      if (code === 45) { // -
+    }
+    if (code >= 48 && code <= 57) { // 0 - 9
+      do {
         code = charCodeAt.call(body, ++position);
-      }
-      if (code >= 48 && code <= 57) { // 0 - 9
-        do {
-          code = charCodeAt.call(body, ++position);
-        } while (code >= 48 && code <= 57); // 0 - 9
-      } else {
-        throw syntaxError(source, position, 'Invalid number.');
-      }
+      } while (code >= 48 && code <= 57); // 0 - 9
+    } else {
+      throw syntaxError(source, position, 'Invalid number.');
     }
   }