Use zero-based numeric indices for much faster instrumented code

src/source-coverage.js

@@ -35,15 +35,14 @@ class SourceCoverage extends classes.FileCoverage {
     }
 
     newStatement(loc) {
-        this.meta.last.s += 1;
         var s = this.meta.last.s;
         this.data.statementMap[s] = cloneLocation(loc);
         this.data.s[s] = 0;
+        this.meta.last.s += 1;
         return s;
     }
 
     newFunction(name, decl, loc) {
-        this.meta.last.f += 1;
         var f = this.meta.last.f;
         name = name || '(anonymous_' + f + ')';
         this.data.fnMap[f] = {
@@ -52,18 +51,19 @@ class SourceCoverage extends classes.FileCoverage {
             loc: cloneLocation(loc)
         };
         this.data.f[f] = 0;
+        this.meta.last.f += 1;
         return f;
     }
 
     newBranch(type, loc) {
-        this.meta.last.b += 1;
         var b = this.meta.last.b;
         this.data.b[b] = [];
         this.data.branchMap[b] = {
             loc: cloneLocation(loc),
             type: type,
             locations: []
         };
+        this.meta.last.b += 1;
         return b;
     }
 

src/visitor.js

@@ -91,7 +91,7 @@ class VisitState {
             return;
         }
         // else check custom node attribute set by a prior visitor
-        if (this.getAttr(path.node, 'skip-all')) {
+        if (this.getAttr(path.node, 'skip-all') !== null) {
             this.nextIgnore = n;
         }
     }
@@ -134,7 +134,7 @@ class VisitState {
             wrap(
                 T.memberExpression(
                     T.memberExpression(T.identifier(this.varName), T.identifier(type)),
-                    T.stringLiteral(String(id)),
+                    T.numericLiteral(id),
                     true
                 )
             )
@@ -354,7 +354,7 @@ function coverSwitchCase(path) {
     const T = this.types;
     const b = this.getAttr(path.parentPath.node, 'branchName');
     /* istanbul ignore if: paranoid check */
-    if (!b) {
+    if (b === null) {
         throw new Error('Unable to get switch branch name');
     }
     const increment = this.getBranchIncrement(b, path.node.loc);
@@ -430,7 +430,7 @@ const codeVisitor = {
 // the template to insert at the top of the program.
 const coverageTemplate = template(`
     var COVERAGE_VAR = (function () {
-        var path = PATH, 
+        var path = PATH,
             hash = HASH,
             global = (new Function('return this'))(),
             gcv = GLOBAL_COVERAGE_VAR,

test/specs/arrow-fn.yaml

@@ -9,15 +9,15 @@ tests:
     args: [1, 2, 3, 4]
     out: [1, 4, 9, 16]
     lines: {'1': 1, '2': 4}
-    statements: {'1': 1, '2': 1, '3': 4}
-    functions: {'1': 4}
+    statements: {'0': 1, '1': 1, '2': 4}
+    functions: {'0': 4}
 
   - name: function not called
     args: []
     out: []
     lines: {'1': 1, '2': 1}
-    statements: {'1': 1, '2': 1, '3': 0}
-    functions: {'1': 0}
+    statements: {'0': 1, '1': 1, '2': 0}
+    functions: {'0': 0}
 
 ---
 name:  es6 arrow function block
@@ -30,15 +30,15 @@ tests:
     args: [1, 2, 3, 4]
     out: [1, 4, 9, 16]
     lines: {'1': 1, '2': 4}
-    statements: {'1': 1, '2': 1, '3': 4}
-    functions: {'1': 4}
+    statements: {'0': 1, '1': 1, '2': 4}
+    functions: {'0': 4}
 
   - name: function not called
     args: []
     out: []
     lines: {'1': 1, '2': 1}
-    statements: {'1': 1, '2': 1, '3': 0}
-    functions: {'1': 0}
+    statements: {'0': 1, '1': 1, '2': 0}
+    functions: {'0': 0}
 
 ---
 name: complex arrow fn
@@ -57,6 +57,6 @@ tests:
     args: [1, 2, 3, 4]
     out: 10
     lines: { '1': 1, '2': 1, '3': 1, '4': 1, '8': 1}
-    functions: { '1': 1, '2': 1, '3': 1, '4': 1 }
-    statements: { '1': 1, '2': 1, '3': 1, '4': 1, '5': 1, '6':1 }
+    functions: { '0': 1, '1': 1, '2': 1, '3': 1 }
+    statements: { '0': 1, '1': 1, '2': 1, '3': 1, '4': 1, '5':1 }
 

test/specs/default-args.yaml

@@ -11,22 +11,22 @@ tests:
     args: [10, 20, 30, 40]
     out: 100
     lines: { '2': 1, 4: 1}
-    statements: {'1': 1, '2': 1 }
-    functions: {'1': 1}
-    branches: { '1': [0], '2': [0], '3': [0], '4': [0] }
+    statements: {'0': 1, '1': 1 }
+    functions: {'0': 1}
+    branches: { '0': [0], '1': [0], '2': [0], '3': [0] }
 
   - name: 2 of 4 specified
     args: [3, 4 ]
     out: 14
     lines: { '2': 1, 4: 1}
-    statements: {'1': 1, '2': 1 }
-    functions: {'1': 1}
-    branches: { '1': [0], '2': [0], '3': [1], '4': [1] }
+    statements: {'0': 1, '1': 1 }
+    functions: {'0': 1}
+    branches: { '0': [0], '1': [0], '2': [1], '3': [1] }
 
   - name: nothing specified
     args: []
     out: 10
     lines: { '2': 1, 4: 1}
-    statements: {'1': 1, '2': 1 }
-    functions: {'1': 1}
-    branches: { '1': [1], '2': [1], '3': [1], '4': [1] }
+    statements: {'0': 1, '1': 1 }
+    functions: {'0': 1}
+    branches: { '0': [1], '1': [1], '2': [1], '3': [1] }

test/specs/do-while.yaml

@@ -9,13 +9,13 @@ tests:
     args: [10]
     out: 10
     lines: {'1': 1, '2': 10, '3': 1}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 10, '5': 1}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 10, '4': 1}
 
   - name: single entry into while
     args: [-1]
     out: 1
     lines: {'1': 1, '2': 1, '3': 1}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 1, '5': 1}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 1, '4': 1}
 
 ---
 name: block do-while on separate line
@@ -30,13 +30,13 @@ tests:
     args: [10]
     out: 10
     lines: {'1': 1, '2': 1, '3': 10, '5': 1}
-    statements: {'1': 1, '2':1, '3': 1, '4': 10, '5': 1}
+    statements: {'0': 1, '1':1, '2': 1, '3': 10, '4': 1}
 
   - name: single entry into while
     args: [-1]
     out: 1
     lines: {'1': 1, '2': 1, '3': 1, '5': 1}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 1, '5': 1}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 1, '4': 1}
 
 ---
 name: ignore inside do-while
@@ -50,4 +50,4 @@ tests:
   - args: []
     out: 10
     lines: {'1': 1, '5': 1}
-    statements: {'1': 1, '2': 1 }
+    statements: {'0': 1, '1': 1 }

test/specs/expressions.yaml

@@ -8,22 +8,22 @@ tests:
     args: [-1]
     out: false
     lines: {'1': 1, '2': 1}
-    branches: {'1': [1, 0]}
-    statements: {'1': 1, '2': 1}
+    branches: {'0': [1, 0]}
+    statements: {'0': 1, '1': 1}
 
   - name: covers line, both branches, returns false
     args: [10]
     out: false
     lines: {'1': 1, '2': 1}
-    branches: {'1': [1, 1]}
-    statements: {'1': 1, '2': 1}
+    branches: {'0': [1, 1]}
+    statements: {'0': 1, '1': 1}
 
   - name: covers line, both branches, returns true
     args: [3]
     out: true
     lines: {'1': 1, '2': 1}
-    branches: {'1': [1, 1]}
-    statements: {'1': 1, '2': 1}
+    branches: {'0': [1, 1]}
+    statements: {'0': 1, '1': 1}
 
 ---
 name: complex expression
@@ -35,22 +35,22 @@ tests:
     args: [-1]
     out: false
     lines: {'1': 1, '2': 1}
-    branches: {'1': [1, 0, 0]}
-    statements: {'1': 1, '2': 1}
+    branches: {'0': [1, 0, 0]}
+    statements: {'0': 1, '1': 1}
 
   - name: covers line, both branches, returns false
     args: [9]
     out: false
     lines: {'1': 1, '2': 1}
-    branches: {'1': [1, 1, 1]}
-    statements: {'1': 1, '2': 1}
+    branches: {'0': [1, 1, 1]}
+    statements: {'0': 1, '1': 1}
 
   - name: covers line, both branches, returns true
     args: [3]
     out: true
     lines: {'1': 1, '2': 1}
-    branches: {'1': [1, 1, 0]}
-    statements: {'1': 1, '2': 1}
+    branches: {'0': [1, 1, 0]}
+    statements: {'0': 1, '1': 1}
 
 ---
 name: array expression with empty positions
@@ -62,8 +62,8 @@ tests:
     args: [1,5]
     out: true
     lines: {'1': 1, '2': 1}
-    branches: { 1: [1, 1] }
-    statements: {'1': 1, '2': 1}
+    branches: { '0': [1, 1] }
+    statements: {'0': 1, '1': 1}
 
 ---
 name: or with object expression (bug track)
@@ -75,8 +75,8 @@ tests:
     args: [ false ]
     out: 2
     lines: {'1': 1, '2': 1}
-    branches: { 1: [0, 1] }
-    statements: {'1': 1, '2': 1}
+    branches: { '0': [0, 1] }
+    statements: {'0': 1, '1': 1}
 
 ---
 name: or with object expression (part 2)
@@ -88,5 +88,5 @@ tests:
     args: [ false ]
     out: 2
     lines: {'1': 1, '2': 1}
-    branches: { 1: [1, 1] }
-    statements: {'1': 1, '2': 1}
+    branches: { '0': [1, 1] }
+    statements: {'0': 1, '1': 1}

test/specs/for-in.yaml

@@ -12,8 +12,8 @@ tests:
   - args: [10, 0]
     out: 10
     lines: {'1': 1, '2': 1, '3': 1, '4': 2, '5': 1}
-    branches: {'1': [1, 1], '2': [2, 2]}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 2, '5': 1}
+    branches: {'0': [1, 1], '1': [2, 2]}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 2, '4': 1}
 
 ---
 name: for-in with loop initializer
@@ -29,5 +29,5 @@ tests:
   - args: [10, 0]
     out: 10
     lines: {'1': 1, '2': 1, '3': 1, '4': 2, '5': 1}
-    branches: {'1': [1, 1], '2': [2, 2]}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 2, '5': 1}
+    branches: {'0': [1, 1], '1': [2, 2]}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 2, '4': 1}

test/specs/for-of.yaml

@@ -12,8 +12,8 @@ tests:
   - args: []
     out: 3
     lines: {'1': 1, '3': 1, '4': 1, '5': 2}
-    functions: {'1': 1}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 1, '5': 2}
+    functions: {'0': 1}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 1, '4': 2}
 ---
 
 name: for-of with loop initializer
@@ -28,5 +28,5 @@ tests:
   - args: []
     out: 3
     lines: {'1': 1, '2': 1, '3': 1, '4': 2}
-    functions: {'1': 1}
-    statements: {'1': 1, '2': 1, '3': 1, '4': 1, '5': 2}
+    functions: {'0': 1}
+    statements: {'0': 1, '1': 1, '2': 1, '3': 1, '4': 2}