handlebars.js/spec/subexpressions.js

/*global CompilerContext, shouldCompileTo */
describe('subexpressions', function() {
  it("arg-less helper", function() {
    var string   = "{{foo (bar)}}!";
    var context  = {};
    var helpers  = {
      foo: function(val) {
        return val+val;
      },
      bar: function() {
        return "LOL";
      }
    };
    shouldCompileTo(string, [context, helpers], "LOLLOL!");
  });

  it("helper w args", function() {
    var string   = '{{blog (equal a b)}}';

    var context  = { bar: "LOL" };
    var helpers  = {
      blog: function(val) {
        return "val is " + val;
      },
      equal: function(x, y) {
        return x === y;
      }
    };
    shouldCompileTo(string, [context, helpers], "val is true");
  });

  it("mixed paths and helpers", function() {
    var string   = '{{blog baz.bat (equal a b) baz.bar}}';

    var context  = { bar: "LOL", baz: {bat: 'foo!', bar: 'bar!'} };
    var helpers  = {
      blog: function(val, that, theOther) {
        return "val is " + val + ', ' + that + ' and ' + theOther;
      },
      equal: function(x, y) {
        return x === y;
      }
    };
    shouldCompileTo(string, [context, helpers], "val is foo!, true and bar!");
  });

  it("supports much nesting", function() {
    var string   = '{{blog (equal (equal true true) true)}}';

    var context  = { bar: "LOL" };
    var helpers  = {
      blog: function(val) {
        return "val is " + val;
      },
      equal: function(x, y) {
        return x === y;
      }
    };
    shouldCompileTo(string, [context, helpers], "val is true");
  });

  it("provides each nested helper invocation its own options hash", function() {
    var string = '{{equal (equal true true) true}}';

    var lastOptions = null;
    var helpers  = {
      equal: function(x, y, options) {
        if (!options || options === lastOptions) {
          throw new Error("options hash was reused");
        }
        lastOptions = options;
        return x === y;
      }
    };
    shouldCompileTo(string, [{}, helpers], "true");
  });

  it("with hashes", function() {
    var string   = '{{blog (equal (equal true true) true fun="yes")}}';

    var context  = { bar: "LOL" };
    var helpers  = {
      blog: function(val) {
        return "val is " + val;
      },
      equal: function(x, y) {
        return x === y;
      }
    };
    shouldCompileTo(string, [context, helpers], "val is true");
  });

  it("as hashes", function() {
    var string   = '{{blog fun=(equal (blog fun=1) "val is 1")}}';

    var helpers  = {
      blog: function(options) {
        return "val is " + options.hash.fun;
      },
      equal: function(x, y) {
        return x === y;
      }
    };
    shouldCompileTo(string, [{}, helpers], "val is true");
  });

  it("multiple subexpressions in a hash", function() {
    var string = '{{input aria-label=(t "Name") placeholder=(t "Example User")}}';

    var helpers = {
      input: function(options) {
        var hash        = options.hash;
        var ariaLabel   = Handlebars.Utils.escapeExpression(hash['aria-label']);
        var placeholder = Handlebars.Utils.escapeExpression(hash.placeholder);
        return new Handlebars.SafeString('<input aria-label="' + ariaLabel + '" placeholder="' + placeholder + '" />');
      },
      t: function(defaultString) {
        return new Handlebars.SafeString(defaultString);
      }
    }
    shouldCompileTo(string, [{}, helpers], '<input aria-label="Name" placeholder="Example User" />');
  });

  it("in string params mode,", function() {
    var template = CompilerContext.compile('{{snog (blorg foo x=y) yeah a=b}}', {stringParams: true});

    var helpers = {
      snog: function(a, b, options) {
        equals(a, 'foo');
        equals(options.types.length, 2, "string params for outer helper processed correctly");
        equals(options.types[0], 'sexpr', "string params for outer helper processed correctly");
        equals(options.types[1], 'ID', "string params for outer helper processed correctly");
        return a + b;
      },

      blorg: function(a, options) {
        equals(options.types.length, 1, "string params for inner helper processed correctly");
        equals(options.types[0], 'ID', "string params for inner helper processed correctly");
        return a;
      }
    };

    var result = template({
      foo: {},
      yeah: {}
    }, {helpers: helpers});

    equals(result, "fooyeah");
  });

  it("as hashes in string params mode", function() {

    var template = CompilerContext.compile('{{blog fun=(bork)}}', {stringParams: true});

    var helpers  = {
      blog: function(options) {
        equals(options.hashTypes.fun, 'sexpr');
        return "val is " + options.hash.fun;
      },
      bork: function() {
        return "BORK";
      }
    };

    var result = template({}, {helpers: helpers});
    equals(result, "val is BORK");
  });

  it("subexpression functions on the context", function() {
    var string   = "{{foo (bar)}}!";
    var context  = {
      bar: function() {
        return "LOL";
      }
    };
    var helpers  = {
      foo: function(val) {
        return val+val;
      }
    };
    shouldCompileTo(string, [context, helpers], "LOLLOL!");
  });

  it("subexpressions can't just be property lookups", function() {
    var string   = "{{foo (bar)}}!";
    var context  = {
      bar: "LOL"
    };
    var helpers  = {
      foo: function(val) {
        return val+val;
      }
    };
    shouldThrow(function() {
      shouldCompileTo(string, [context, helpers], "LOLLOL!");
    });
  });
});