Auto merge of #7203 - jdm:style, r=Ms2ger

Add automated style nit checks to test-tidy

Expands on the work by @wilmoz and cleans up the existing errors. Closes #7180. Closes #7111.

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/7203)
<!-- Reviewable:end -->

components/gfx/platform/freetype/font_list.rs

@@ -8,17 +8,11 @@ extern crate freetype;
 extern crate fontconfig;
 
 use fontconfig::fontconfig::{FcChar8, FcResultMatch, FcSetSystem};
-use fontconfig::fontconfig::{
+use fontconfig::fontconfig::{FcConfigGetCurrent, FcConfigGetFonts, FcConfigSubstitute};
-    FcConfigGetCurrent, FcConfigGetFonts,
+use fontconfig::fontconfig::{FcDefaultSubstitute, FcFontMatch, FcNameParse, FcPatternGetString};
-    FcConfigSubstitute, FcDefaultSubstitute,
+use fontconfig::fontconfig::{FcPatternDestroy, FcFontSetDestroy, FcMatchPattern, FcPatternCreate};
-    FcFontMatch,
+use fontconfig::fontconfig::{FcPatternAddString, FcFontSetList, FcObjectSetCreate, FcObjectSetDestroy};
-    FcNameParse, FcPatternGetString,
+use fontconfig::fontconfig::{FcObjectSetAdd, FcPatternGetInteger};
-    FcPatternDestroy, FcFontSetDestroy,
-    FcMatchPattern,
-    FcPatternCreate, FcPatternAddString,
-    FcFontSetList, FcObjectSetCreate, FcObjectSetDestroy,
-    FcObjectSetAdd, FcPatternGetInteger
-};
 
 use util::str::c_str_to_string;
 

components/layout/display_list_builder.rs

@@ -45,10 +45,10 @@ use std::sync::Arc;
 use std::sync::mpsc::channel;
 use std::f32;
 use style::computed_values::filter::Filter;
-use style::computed_values::{background_attachment, background_clip, background_origin,
+use style::computed_values::{background_attachment, background_clip, background_origin};
-                             background_repeat, background_size};
+use style::computed_values::{background_repeat, background_size};
-use style::computed_values::{border_style, image_rendering, overflow_x, position,
+use style::computed_values::{border_style, image_rendering, overflow_x, position};
-                             visibility, transform, transform_style};
+use style::computed_values::{visibility, transform, transform_style};
 use style::properties::ComputedValues;
 use style::properties::style_structs::Border;
 use style::values::RGBA;

components/plugins/jstraceable.rs

@@ -8,8 +8,8 @@ use syntax::ptr::P;
 use syntax::ast::{MetaItem, Expr};
 use syntax::ast;
 use syntax::ext::build::AstBuilder;
-use syntax::ext::deriving::generic::{combine_substructure, EnumMatching, FieldInfo, MethodDef, Struct,
+use syntax::ext::deriving::generic::{combine_substructure, EnumMatching, FieldInfo, MethodDef};
-                                     Substructure, TraitDef, ty};
+use syntax::ext::deriving::generic::{Struct, Substructure, TraitDef, ty};
 
 pub fn expand_dom_struct(cx: &mut ExtCtxt, sp: Span, _: &MetaItem, anno: Annotatable) -> Annotatable {
     if let Annotatable::Item(item) = anno {

components/script/dom/canvasrenderingcontext2d.rs

@@ -191,8 +191,10 @@ impl CanvasRenderingContext2D {
 
         // The destination rectangle is the rectangle whose corners are the four points (dx, dy),
         // (dx+dw, dy), (dx+dw, dy+dh), (dx, dy+dh).
-        let dest_rect = Rect::new(Point2D::new(dx.min(dx+dest_rect_width_scaled), dy.min(dy+dest_rect_height_scaled)),
+        let dest_rect = Rect::new(Point2D::new(dx.min(dx + dest_rect_width_scaled),
-                                  Size2D::new(dest_rect_width_scaled.abs(), dest_rect_height_scaled.abs()));
+                                               dy.min(dy + dest_rect_height_scaled)),
+                                  Size2D::new(dest_rect_width_scaled.abs(),
+                                              dest_rect_height_scaled.abs()));
 
         let source_rect = Rect::new(Point2D::new(source_rect_clipped.origin.x,
                                                  source_rect_clipped.origin.y),

components/script/dom/htmliframeelement.rs

@@ -7,8 +7,8 @@ use dom::bindings::codegen::Bindings::HTMLIFrameElementBinding;
 use dom::bindings::codegen::Bindings::HTMLIFrameElementBinding::HTMLIFrameElementMethods;
 use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use dom::bindings::codegen::InheritTypes::{NodeCast, ElementCast, EventCast};
-use dom::bindings::codegen::InheritTypes::{EventTargetCast, HTMLElementCast,
+use dom::bindings::codegen::InheritTypes::{EventTargetCast, HTMLElementCast};
-                                           HTMLIFrameElementDerived};
+use dom::bindings::codegen::InheritTypes::HTMLIFrameElementDerived;
 use dom::bindings::conversions::ToJSValConvertible;
 use dom::bindings::error::{ErrorResult, Fallible};
 use dom::bindings::error::Error::NotSupported;

components/script/dom/htmlimageelement.rs

@@ -8,8 +8,8 @@ use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::HTMLImageElementBinding;
 use dom::bindings::codegen::Bindings::HTMLImageElementBinding::HTMLImageElementMethods;
 use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
-use dom::bindings::codegen::InheritTypes::{NodeCast, ElementCast, EventTargetCast, HTMLElementCast,
+use dom::bindings::codegen::InheritTypes::{NodeCast, ElementCast, EventTargetCast};
-                                           HTMLImageElementDerived};
+use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLImageElementDerived};
 use dom::bindings::error::Fallible;
 use dom::bindings::global::GlobalRef;
 use dom::bindings::js::{LayoutJS, Root};

components/script/script_task.rs

@@ -32,8 +32,8 @@ use dom::bindings::js::{RootCollectionPtr, Root, RootedReference};
 use dom::bindings::refcounted::{LiveDOMReferences, Trusted, TrustedReference, trace_refcounted_objects};
 use dom::bindings::trace::{JSTraceable, trace_traceables, RootedVec};
 use dom::bindings::utils::{WRAP_CALLBACKS, DOM_CALLBACKS};
-use dom::document::{Document, IsHTMLDocument, DocumentHelpers, DocumentProgressHandler,
+use dom::document::{Document, IsHTMLDocument, DocumentHelpers, DocumentProgressHandler};
-                    DocumentProgressTask, DocumentSource, MouseEventType};
+use dom::document::{DocumentProgressTask, DocumentSource, MouseEventType};
 use dom::element::{Element, AttributeHandlers};
 use dom::event::{EventHelpers, EventBubbles, EventCancelable};
 use dom::htmliframeelement::HTMLIFrameElementHelpers;

components/style/stylesheets.rs

@@ -10,8 +10,8 @@ use url::Url;
 
 use encoding::EncodingRef;
 
-use cssparser::{Parser, decode_stylesheet_bytes,
+use cssparser::{Parser, decode_stylesheet_bytes, QualifiedRuleParser, AtRuleParser};
-                QualifiedRuleParser, AtRuleParser, RuleListParser, AtRuleType};
+use cssparser::{RuleListParser, AtRuleType};
 use string_cache::{Atom, Namespace};
 use selectors::parser::{Selector, parse_selector_list};
 use parser::{ParserContext, log_css_error};

components/webdriver_server/lib.rs

@@ -19,18 +19,17 @@ extern crate rustc_serialize;
 extern crate uuid;
 extern crate ipc_channel;
 
-use msg::constellation_msg::{ConstellationChan, LoadData, FrameId, PipelineId, NavigationDirection,
+use msg::constellation_msg::{ConstellationChan, LoadData, FrameId, PipelineId};
-                             WebDriverCommandMsg};
+use msg::constellation_msg::{NavigationDirection, WebDriverCommandMsg};
 use msg::constellation_msg::Msg as ConstellationMsg;
 use msg::webdriver_msg::{WebDriverFrameId, WebDriverScriptCommand, WebDriverJSError, WebDriverJSResult, LoadStatus};
 
 use url::Url;
 use webdriver::command::{WebDriverMessage, WebDriverCommand};
-use webdriver::command::{GetParameters, JavascriptCommandParameters, LocatorParameters,
+use webdriver::command::{GetParameters, JavascriptCommandParameters, LocatorParameters};
-                         SwitchToFrameParameters, TimeoutsParameters};
+use webdriver::command::{SwitchToFrameParameters, TimeoutsParameters};
 use webdriver::common::{LocatorStrategy, WebElement};
-use webdriver::response::{
+use webdriver::response::{WebDriverResponse, NewSessionResponse, ValueResponse};
-    WebDriverResponse, NewSessionResponse, ValueResponse};
 use webdriver::server::{self, WebDriverHandler, Session};
 use webdriver::error::{WebDriverResult, WebDriverError, ErrorStatus};
 use util::task::spawn_named;

ports/gonk/src/input.rs

@@ -204,7 +204,8 @@ fn read_input_device(device_path: &Path,
                                      cur_dist, last_dist, screen_dist,
                                      ((screen_dist + (cur_dist - last_dist)) / screen_dist));
                             sender.send(
-                                WindowEvent::Zoom((screen_dist + (cur_dist - last_dist))/screen_dist)).ok().unwrap();
+                                WindowEvent::Zoom((screen_dist + (cur_dist - last_dist)) /
+                                                  screen_dist)).ok().unwrap();
                             last_dist = cur_dist;
                         }
                     }

python/tidy.py

@@ -165,6 +165,93 @@ def check_toml(file_name, contents):
             yield (idx + 1, "found asterisk instead of minimum version number")
 
 
+def check_rust(file_name, contents):
+    if not file_name.endswith(".rs") or \
+       file_name.endswith("properties.mako.rs") or \
+       file_name.endswith("style/build.rs") or \
+       file_name.endswith("unit/style/stylesheets.rs"):
+        raise StopIteration
+    contents = contents.splitlines(True)
+    comment_depth = 0
+    merged_lines = ''
+    for idx, line in enumerate(contents):
+        # simplify the analysis
+        line = line.strip()
+
+        # Simple heuristic to avoid common case of no comments.
+        if '/' in line:
+            comment_depth += line.count('/*')
+            comment_depth -= line.count('*/')
+
+        if line.endswith('\\'):
+            merged_lines += line[:-1]
+            continue
+        if comment_depth:
+            merged_lines += line
+            continue
+        if merged_lines:
+            line = merged_lines + line
+            merged_lines = ''
+
+        # get rid of strings and chars because cases like regex expression
+        line = re.sub('".*?"|\'.*?\'', '', line)
+
+        # get rid of comments and attributes
+        line = re.sub('//.*?$|/\*.*?$|^\*.*?$|^#.*?$', '', line)
+
+        match = re.search(r",[A-Za-z0-9]", line)
+        if match:
+            yield (idx + 1, "missing space after ,")
+
+        # Avoid flagging <Item=Foo> constructs
+        def is_associated_type(match, line, index):
+            open_angle = line[0:match.end()].rfind('<')
+            close_angle = line[open_angle:].find('>') if open_angle != -1 else -1
+            is_equals = match.group(0)[index] == '='
+            generic_open = open_angle != -1 and open_angle < match.start()
+            generic_close = close_angle != -1 and close_angle + open_angle >= match.end()
+            return is_equals and generic_open and generic_close
+
+        # - not included because of scientific notation (1e-6)
+        match = re.search(r"[A-Za-z0-9][\+/\*%=]", line)
+        if match and not is_associated_type(match, line, 1):
+            yield (idx + 1, "missing space before %s" % match.group(0)[1])
+
+        # * not included because of dereferencing and casting
+        # - not included because of unary negation
+        match = re.search(r"[\+/\%=][A-Za-z0-9]", line)
+        if match and not is_associated_type(match, line, 0):
+            yield (idx + 1, "missing space after %s" % match.group(0)[0])
+
+        match = re.search(r"\)->", line)
+        if match:
+            yield (idx + 1, "missing space before ->")
+
+        match = re.search(r"->[A-Za-z]", line)
+        if match:
+            yield (idx + 1, "missing space after ->")
+
+        # Avoid flagging ::crate::mod and `trait Foo : Bar`
+        match = line.find(" :")
+        if match != -1:
+            if line[0:match].find('trait ') == -1 and line[match + 2] != ':':
+                yield (idx + 1, "extra space before :")
+
+        # Avoid flagging crate::mod
+        match = re.search(r"[^:]:[A-Za-z]", line)
+        if match:
+            # Avoid flagging macros like $t1:expr
+            if line[0:match.end()].rfind('$') == -1:
+                yield (idx + 1, "missing space after :")
+
+        match = re.search(r"[A-Za-z0-9\)]{", line)
+        if match:
+            yield (idx + 1, "missing space before {")
+
+        if line.startswith("use ") and "{" in line and "}" not in line:
+            yield (idx + 1, "use statement spans multiple lines")
+
+
 def check_webidl_spec(file_name, contents):
     # Sorted by this function (in pseudo-Rust). The idea is to group the same
     # organization together.
@@ -278,7 +365,8 @@ def scan():
     all_files = collect_file_names()
     files_to_check = filter(should_check, all_files)
 
-    checking_functions = [check_license, check_by_line, check_flake8, check_toml, check_webidl_spec, check_spec]
+    checking_functions = [check_license, check_by_line, check_flake8, check_toml,
+                          check_rust, check_webidl_spec, check_spec]
     errors = collect_errors_for_files(files_to_check, checking_functions)
 
     reftest_files = collect_file_names(reftest_directories)

tests/unit/util/logical_geometry.rs

@@ -3,8 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use euclid::{Size2D, Point2D, SideOffsets2D, Rect};
-use util::logical_geometry::{WritingMode, LogicalSize, LogicalPoint, LogicalMargin, LogicalRect,
+use util::logical_geometry::{WritingMode, LogicalSize, LogicalPoint, LogicalMargin, LogicalRect};
-                             FLAG_RTL, FLAG_VERTICAL, FLAG_VERTICAL_LR, FLAG_SIDEWAYS_LEFT};
+use util::logical_geometry::{FLAG_RTL, FLAG_VERTICAL, FLAG_VERTICAL_LR, FLAG_SIDEWAYS_LEFT};
 
 #[cfg(test)]
 fn modes() -> [WritingMode; 10] {