Clarify pathname docs, follow spec with fragments (#2448)

* Clarify pathname docs, follow spec with fragments

- Valid URLs must not contain a `#` within its fragment.
  https://github.com/MithrilJS/mithril.js/issues/2445
- Our docs were a little confusing and misleading - `m.pathname` isn't
  aware of URLs, just path names.
- Removed the relevant extension to `m.parseQueryString` required to
  support the hash parsing extension. Now we just shave it off and
  ignore it.
- Fix support for arbitrary prefixes, so prefixes like `?#` are
  handled correctly.
- Add a bunch of tests to cover various areas of confusion and unusual
  edge cases.

* Update with PR [skip ci]

pathname/parse.js

@@ -9,16 +9,16 @@ module.exports = function(url) {
 	var queryEnd = hashIndex < 0 ? url.length : hashIndex
 	var pathEnd = queryIndex < 0 ? queryEnd : queryIndex
 	var path = url.slice(0, pathEnd).replace(/\/{2,}/g, "/")
-	var params = {}
 
 	if (!path) path = "/"
 	else {
 		if (path[0] !== "/") path = "/" + path
 		if (path.length > 1 && path[path.length - 1] === "/") path = path.slice(0, -1)
 	}
-	// Note: these are reversed because `parseQueryString` appends parameters
-	// only if they don't exist. Please don't flip them.
-	if (queryIndex >= 0) parseQueryString(url.slice(queryIndex + 1, queryEnd), params)
-	if (hashIndex >= 0) parseQueryString(url.slice(hashIndex + 1), params)
-	return {path: path, params: params}
+	return {
+		path: path,
+		params: queryIndex < 0
+			? {}
+			: parseQueryString(url.slice(queryIndex + 1, queryEnd)),
+	}
 }

pathname/tests/test-compileTemplate.js

@@ -198,18 +198,6 @@ o.spec("compileTemplate", function() {
 		o(compileTemplate("/route/:id?bar=foo")(data)).equals(false)
 		o(data.params).deepEquals({foo: "bar"})
 	})
-	o("checks hash params match", function() {
-		var data = parsePathname("/route/1#foo=bar")
-		o(compileTemplate("/route/:id#foo=bar")(data)).equals(true)
-		o(data.params).deepEquals({id: "1", foo: "bar"})
-	})
-	o("checks hash params mismatch", function() {
-		var data = parsePathname("/route/1#foo=bar")
-		o(compileTemplate("/route/:id#foo=1")(data)).equals(false)
-		o(data.params).deepEquals({foo: "bar"})
-		o(compileTemplate("/route/:id#bar=foo")(data)).equals(false)
-		o(data.params).deepEquals({foo: "bar"})
-	})
 	o("checks dot before dot", function() {
 		var data = parsePathname("/file.test.png/edit")
 		o(compileTemplate("/:file.:ext/edit")(data)).equals(true)

pathname/tests/test-parsePathname.js

@@ -18,18 +18,18 @@ o.spec("parsePathname", function() {
 			params: {a: "b", c: "d"}
 		})
 	})
-	o("parses hash at start", function() {
+	o("ignores hash at start", function() {
 		var data = parsePathname("#a=b&c=d")
 		o(data).deepEquals({
 			path: "/",
-			params: {a: "b", c: "d"}
+			params: {}
 		})
 	})
-	o("parses query + hash at start", function() {
+	o("parses query, ignores hash at start", function() {
 		var data = parsePathname("?a=1&b=2#c=3&d=4")
 		o(data).deepEquals({
 			path: "/",
-			params: {a: "1", b: "2", c: "3", d: "4"}
+			params: {a: "1", b: "2"}
 		})
 	})
 	o("parses root", function() {
@@ -46,18 +46,18 @@ o.spec("parsePathname", function() {
 			params: {a: "b", c: "d"}
 		})
 	})
-	o("parses root + hash at start", function() {
+	o("parses root, ignores hash at start", function() {
 		var data = parsePathname("/#a=b&c=d")
 		o(data).deepEquals({
 			path: "/",
-			params: {a: "b", c: "d"}
+			params: {}
 		})
 	})
-	o("parses root + query + hash at start", function() {
+	o("parses root + query, ignores hash at start", function() {
 		var data = parsePathname("/?a=1&b=2#c=3&d=4")
 		o(data).deepEquals({
 			path: "/",
-			params: {a: "1", b: "2", c: "3", d: "4"}
+			params: {a: "1", b: "2"}
 		})
 	})
 	o("parses route", function() {
@@ -102,25 +102,25 @@ o.spec("parsePathname", function() {
 			params: {c: "3", d: "4"}
 		})
 	})
-	o("parses route + query + hash", function() {
+	o("parses route + query, ignores hash", function() {
 		var data = parsePathname("/route/foo?a=1&b=2#c=3&d=4")
 		o(data).deepEquals({
 			path: "/route/foo",
-			params: {a: "1", b: "2", c: "3", d: "4"}
+			params: {a: "1", b: "2"}
 		})
 	})
-	o("deduplicates same-named params in query + hash", function() {
-		var data = parsePathname("/route/foo?a=1&b=2#a=3&c=4")
-		o(data).deepEquals({
-			path: "/route/foo",
-			params: {a: "3", b: "2", c: "4"}
-		})
-	})
-	o("parses route + query + hash with lots of junk slashes", function() {
+	o("parses route + query, ignores hash with lots of junk slashes", function() {
 		var data = parsePathname("//route/////foo//?a=1&b=2#c=3&d=4")
 		o(data).deepEquals({
 			path: "/route/foo",
-			params: {a: "1", b: "2", c: "3", d: "4"}
+			params: {a: "1", b: "2"}
+		})
+	})
+	o("doesn't comprehend protocols", function() {
+		var data = parsePathname("https://example.com/foo/bar")
+		o(data).deepEquals({
+			path: "/https:/example.com/foo/bar",
+			params: {}
 		})
 	})
 })