Branch Coverage - else statement location is always the same as if statement location

[shaicantor]

Hi there,

In the instrumenter code while walking on an if statement node and building the branch map I've noticed that the else statement locations is always the same as the if statement locations. Why is that?

The code that does this is located here - https://github.com/gotwarlost/istanbul/blob/master/lib/instrumenter.js#L978

ifBranchInjector: function (node, walker) {
            var alreadyIgnoring = !!this.currentState.ignoring,
                hint = this.currentState.currentHint,
                ignoreThen = !alreadyIgnoring && hint && hint.type === 'if',
                ignoreElse = !alreadyIgnoring && hint && hint.type === 'else',
                line = node.loc.start.line,
                col = node.loc.start.column,
                makeLoc = function () { return  { line: line, column: col }; },
                bName = this.branchName('if', walker.startLineForNode(node), [
                    { start: makeLoc(), end: makeLoc(), skip: ignoreThen || undefined },
                    { start: makeLoc(), end: makeLoc(), skip: ignoreElse || undefined }
                ]),
                thenBody = node.consequent.body,
                elseBody = node.alternate.body,
                child;
            thenBody.unshift(astgen.statement(this.branchIncrementExprAst(bName, 0)));
            elseBody.unshift(astgen.statement(this.branchIncrementExprAst(bName, 1)));
            if (ignoreThen) { child = node.consequent; child.preprocessor = this.startIgnore; child.postprocessor = this.endIgnore; }
            if (ignoreElse) { child = node.alternate; child.preprocessor = this.startIgnore; child.postprocessor = this.endIgnore; }
        }

[seanpoulter]

Did you ever follow-up on this issue in the new monorepo @shaicantor? This is the only relevant Issue I could find ...

[shaicantor]

@seanpoulter, no. We moved to nyc and istanbul-lib-instrument. If I'm not mistaken, it has the same issue there as well.

https://github.com/istanbuljs/istanbuljs/blob/master/packages/istanbul-lib-instrument/src/visitor.js#L362

[seanpoulter]

Yea, istanbul-lib-instrument has the same behavior. I've opened istanbuljs/istanbuljs#130 with the same name. Thanks @shaicantor.