%f should use parseFloat()

[jcbhmr]

if im not mistaken, this

deno/ext/console/01_console.js

Lines 3120 to 3127 in a1d823e

	} else if (char == "f") {
	// Format as a floating point value.
	const value = args[a++];
	if (typeof value == "number") {
	formattedArg = `${value}`;
	} else {
	formattedArg = "NaN";
	}

should be

// Format as a floating point value.
const value = args[a++];
if (typeof value == "symbol") {
  formattedArg = "NaN";
} else {
  formattedArg = `${NumberParseFloat(value)}`;
}

according to the spec:

1. If specifier is %f:

   1. If Type(current) is Symbol, let converted be NaN

   2. Otherwise, let converted be the result of Call(%parseFloat%, undefined, « current »).

https://console.spec.whatwg.org/#formatter

example of bug:

class Frac {
  constructor(num, den) {
    this.num = num
    this.den = den
  }
  [Symbol.toPrimitive]() {
    return this.num / this.den
  }
}
console.log("%f", new Frac(1, 2))

should print: 0.5

In Chrome:

class Frac {
  constructor(num, den) {
    this.num = num
    this.den = den
  }
  [Symbol.toPrimitive]() {
    return this.num / this.den
  }
}
console.log("%f", new Frac(1, 2))
VM382:10 0.5

Firefox:

class Frac {
  constructor(num, den) {
    this.num = num
    this.den = den
  }…
0.500000

https://bugzilla.mozilla.org/show_bug.cgi?id=1846606

current Deno:

jcbhmr@PIG-2016:~/Documents$ deno
Deno 1.38.3
exit using ctrl+d, ctrl+c, or close()
REPL is running with all permissions allowed.
To specify permissions, run `deno repl` with allow flags.
> class Frac {
  constructor(num, den) {
    this.num = num
    this.den = den
  }
  [Symbol.toPrimitive]() {
    return this.num / this.den
  }
}
> console.log("%f", new Frac(1, 2))
NaN
undefined