Added a proper support for cargo --message-format json

Massively refactored code, so the error mode behaviour is less dependent on conditions and more polymorphic.

Author: White-Oak

lib/linter-rust.coffee

@@ -4,13 +4,9 @@ XRegExp = require 'xregexp'
 semver = require 'semver'
 sb_exec = require 'sb-exec'
 {CompositeDisposable} = require 'atom'
-
+errorModes = require './mode'
 
 class LinterRust
-  pattern: XRegExp('(?<file>[^\n\r]+):(?<from_line>\\d+):(?<from_col>\\d+):\\s*\
-    (?<to_line>\\d+):(?<to_col>\\d+)\\s+\
-    ((?<error>error|fatal error)|(?<warning>warning)|(?<info>note|help)):\\s+\
-    (?<message>.+?)[\n\r]+($|(?=[^\n\r]+:\\d+))', 's')
   patternRustcVersion: XRegExp('rustc (?<version>1.\\d+.\\d+)(?:(?:-(?<nightly>nightly)|(?:[^\\s]+))? \
                                 \\((?:[^\\s]+) (?<date>\\d{4}-\\d{2}-\\d{2})\\))?')
   cargoDependencyDir: "target/debug/deps"
@@ -59,209 +55,80 @@ class LinterRust
     do @subscriptions.dispose
 
   lint: (textEditor) =>
-    curDir = path.dirname textEditor.getPath()
-    @ableToJSONErrors(curDir).then (ableToJSONErrors) =>
-      @initCmd(textEditor.getPath(), ableToJSONErrors).then (result) =>
-        [file, cmd] = result
-        env = JSON.parse JSON.stringify process.env
-        curDir = path.dirname file
-        cwd = curDir
-        command = cmd[0]
-        args = cmd.slice 1
-        env.PATH = path.dirname(cmd[0]) + path.delimiter + env.PATH
-
-        if ableToJSONErrors
-          if !env.RUSTFLAGS? or !(env.RUSTFLAGS.indexOf('--error-format=json') >= 0)
-            additional = if env.RUSTFLAGS? then ' ' + env.RUSTFLAGS else ''
-            env.RUSTFLAGS = '--error-format=json' + additional
-        sb_exec.exec(command, args, {env: env, cwd: cwd, stream: 'both'})
-          .then (result) =>
-            {stdout, stderr, exitCode} = result
-            # first, check if an output says specified features are invalid
-            if stderr.indexOf('does not have these features') >= 0
-              atom.notifications.addError "Invalid specified features",
-                detail: "#{stderr}"
-                dismissable: true
-              []
-            # then, if exit code looks okay, process an output
-            else if exitCode is 101 or exitCode is 0
-              # in dev mode show message boxes with output
-              showDevModeWarning = (stream, message) ->
-                atom.notifications.addWarning "Output from #{stream} while linting",
-                  detail: "#{message}"
-                  description: "This is shown because Atom is running in dev-mode and probably not an actual error"
-                  dismissable: true
-              if do atom.inDevMode
-                showDevModeWarning('stderr', stderr) if stderr
-                showDevModeWarning('stdout', stdout) if stdout
-
-              # call a needed parser
-              messages = unless ableToJSONErrors
-                @parse stderr
-              else
-                @parseJSON stderr
-
-              # correct file paths
-              messages.forEach (message) ->
-                if !(path.isAbsolute message.filePath)
-                  message.filePath = path.join curDir, message.filePath
-              messages
-            else
-              # whoops, we're in trouble -- let's output as much as we can
-              atom.notifications.addError "Failed to run #{command} with exit code #{exitCode}",
-                detail: "with args:\n #{args.join(' ')}\nSee console for more information"
-                dismissable: true
-              console.log "stdout:"
-              console.log stdout
-              console.log "stderr:"
-              console.log stderr
-              []
-          .catch (error) ->
-            console.log error
-            atom.notifications.addError "Failed to run #{command}",
-              detail: "#{error.message}"
+    @initCmd(textEditor.getPath()).then (result) =>
+      [cmd_res, errorMode] = result
+      [file, cmd] = cmd_res
+      env = JSON.parse JSON.stringify process.env
+      curDir = path.dirname file
+      cwd = curDir
+      command = cmd[0]
+      args = cmd.slice 1
+      env.PATH = path.dirname(cmd[0]) + path.delimiter + env.PATH
+
+      # we set flags only for intermediate json support
+      if errorMode == errorModes.FLAGS_JSON_CARGO
+        if !env.RUSTFLAGS? or !(env.RUSTFLAGS.indexOf('--error-format=json') >= 0)
+          additional = if env.RUSTFLAGS? then ' ' + env.RUSTFLAGS else ''
+          env.RUSTFLAGS = '--error-format=json' + additional
+
+      sb_exec.exec(command, args, {env: env, cwd: cwd, stream: 'both'})
+        .then (result) =>
+          {stdout, stderr, exitCode} = result
+          # first, check if an output says specified features are invalid
+          if stderr.indexOf('does not have these features') >= 0
+            atom.notifications.addError "Invalid specified features",
+              detail: "#{stderr}"
               dismissable: true
             []
-
-  parseJSON: (output) =>
-    elements = []
-    results = output.split '\n'
-    for result in results
-      if result.startsWith '{'
-        input = JSON.parse result.trim()
-        continue unless input.spans
-        primary_span = input.spans.find (span) -> span.is_primary
-        continue unless primary_span
-        range = [
-          [primary_span.line_start - 1, primary_span.column_start - 1],
-          [primary_span.line_end - 1, primary_span.column_end - 1]
-        ]
-        input.level = 'error' if input == 'fatal error'
-        element =
-          type: input.level
-          message: input.message
-          file: primary_span.file_name
-          range: range
-          children: input.children
-        for span in input.spans
-          unless span.is_primary
-            element.children.push
-              message: span.label
-              range: [
-                [span.line_start - 1, span.column_start - 1],
-                [span.line_end - 1, span.column_end - 1]
-              ]
-        elements.push element
-    @buildMessages(elements)
-
-  parse: (output) =>
-    elements = []
-    XRegExp.forEach output, @pattern, (match) ->
-      if match.from_col == match.to_col
-        match.to_col = parseInt(match.to_col) + 1
-      range = [
-        [match.from_line - 1, match.from_col - 1],
-        [match.to_line - 1, match.to_col - 1]
-      ]
-      level = if match.error then 'error'
-      else if match.warning then 'warning'
-      else if match.info then 'info'
-      else if match.trace then 'trace'
-      else if match.note then 'note'
-      element =
-        type: level
-        message: match.message
-        file: match.file
-        range: range
-      elements.push element
-    @buildMessages elements
-
-  buildMessages: (elements) =>
-    messages = []
-    lastMessage = null
-    for element in elements
-      switch element.type
-        when 'info', 'trace', 'note'
-          # Add only if there is a last message
-          if lastMessage
-            lastMessage.trace or= []
-            lastMessage.trace.push
-              type: "Trace"
-              text: element.message
-              filePath: element.file
-              range: element.range
-        when 'warning'
-          # If the message is warning and user enabled disabling warnings
-          # Check if this warning is disabled
-          if @disabledWarnings and @disabledWarnings.length > 0
-            messageIsDisabledLint = false
-            for disabledWarning in @disabledWarnings
-              # Find a disabled lint in warning message
-              if element.message.indexOf(disabledWarning) >= 0
-                messageIsDisabledLint = true
-                lastMessage = null
-                break
-            if not messageIsDisabledLint
-              lastMessage = @constructMessage "Warning", element
-              messages.push lastMessage
+          # then, if exit code looks okay, process an output
+          else if exitCode is 101 or exitCode is 0
+            # in dev mode show message boxes with output
+            showDevModeWarning = (stream, message) ->
+              atom.notifications.addWarning "Output from #{stream} while linting",
+                detail: "#{message}"
+                description: "This is shown because Atom is running in dev-mode and probably not an actual error"
+                dismissable: true
+            if do atom.inDevMode
+              showDevModeWarning('stderr', stderr) if stderr
+              showDevModeWarning('stdout', stdout) if stdout
+
+            # call a needed parser
+            output = errorMode.neededOutput(stdout, stderr)
+            messages = errorMode.parse output, @disabledWarnings
+
+            # correct file paths
+            messages.forEach (message) ->
+              if !(path.isAbsolute message.filePath)
+                message.filePath = path.join curDir, message.filePath
+            messages
           else
-            lastMessage = @constructMessage "Warning" , element
-            messages.push lastMessage
-        when 'error', 'fatal error'
-          lastMessage = @constructMessage "Error", element
-          messages.push lastMessage
-    return messages
-
-  constructMessage: (type, element) ->
-    message =
-      type: type
-      text: element.message
-      filePath: element.file
-      range: element.range
-    # children exists only in JSON messages
-    if element.children
-      message.trace = []
-      for children in element.children
-        message.trace.push
-          type: "Trace"
-          text: children.message
-          filePath: element.file
-          range: children.range or element.range
-    message
-
-  initCmd: (editingFile, ableToJSONErrors) =>
-    rustcArgs = switch @rustcBuildTest
-      when true then ['--cfg', 'test', '-Z', 'no-trans', '--color', 'never']
-      else ['-Z', 'no-trans', '--color', 'never']
-    cargoArgs = switch @cargoCommand
-      when 'check' then ['check']
-      when 'test' then ['test', '--no-run']
-      when 'rustc' then ['rustc', '-Zno-trans', '--color', 'never']
-      when 'clippy' then ['clippy']
-      else ['build']
-
+            # whoops, we're in trouble -- let's output as much as we can
+            atom.notifications.addError "Failed to run #{command} with exit code #{exitCode}",
+              detail: "with args:\n #{args.join(' ')}\nSee console for more information"
+              dismissable: true
+            console.log "stdout:"
+            console.log stdout
+            console.log "stderr:"
+            console.log stderr
+            []
+        .catch (error) ->
+          console.log error
+          atom.notifications.addError "Failed to run #{command}",
+            detail: "#{error.message}"
+            dismissable: true
+          []
+
+  initCmd: (editingFile) =>
+    curDir = path.dirname editingFile
     cargoManifestPath = @locateCargo path.dirname editingFile
     if not @useCargo or not cargoManifestPath
-      Promise.resolve().then () =>
-        cmd = [@rustcPath]
-          .concat rustcArgs
-        if cargoManifestPath
-          cmd.push '-L'
-          cmd.push path.join path.dirname(cargoManifestPath), @cargoDependencyDir
-        compilationFeatures = @compilationFeatures(false)
-        cmd = cmd.concat compilationFeatures if compilationFeatures
-        cmd = cmd.concat [editingFile]
-        cmd = cmd.concat ['--error-format=json'] if ableToJSONErrors
-        [editingFile, cmd]
+      @decideErrorMode(curDir, 'rustc').then (mode) =>
+        mode.buildArguments(this, [editingFile, cargoManifestPath]).then (cmd) =>
+          [cmd, mode]
     else
-      @buildCargoPath(@cargoPath).then (cmd) =>
-        compilationFeatures = @compilationFeatures(true)
-        cmd = cmd
-          .concat cargoArgs
-          .concat ['-j', @jobsNumber]
-        cmd = cmd.concat compilationFeatures if compilationFeatures
-        cmd = cmd.concat ['--manifest-path', cargoManifestPath]
-        [cargoManifestPath, cmd]
+      @decideErrorMode(curDir, 'cargo').then (mode) =>
+        mode.buildArguments(this, cargoManifestPath).then (cmd) =>
+          [cmd, mode]
 
   compilationFeatures: (cargo) =>
     if @specifiedFeatures.length > 0
@@ -273,19 +140,32 @@ class LinterRust
           result.push ['--cfg', "feature=\"#{f}\""]
         result
 
-  ableToJSONErrors: (curDir) =>
+  decideErrorMode: (curDir, commandMode) =>
     # current dir is set to handle overrides
-
     sb_exec.exec(@rustcPath, ['--version'], {stream: 'stdout', cwd: curDir, stdio: 'pipe'}).then (stdout) =>
-      console.log stdout
       try
         match = XRegExp.exec(stdout, @patternRustcVersion)
-        if match and match.nightly and match.date > '2016-08-08'
-          true
-        else if match and not match.nightly and semver.gte(match.version, '1.12.0')
-          true
+        if match
+          nightlyWithJSON = match.nightly and match.date > '2016-08-08'
+          stableWithJSON = not match.nightly and semver.gte(match.version, '1.12.0')
+          canUseIntermediateJSON = nightlyWithJSON or stableWithJSON
+          switch commandMode
+            when 'cargo'
+              canUseProperCargoJSON = match.nightly and match.date > '2016-10-10'
+              if canUseProperCargoJSON
+                errorModes.JSON_CARGO
+              # this mode is used only through August till October, 2016
+              else if canUseIntermediateJSON
+                errorModes.FLAGS_JSON_CARGO
+              else
+                errorModes.OLD_CARGO
+            when 'rustc'
+              if canUseIntermediateJSON
+                errorModes.JSON_RUSTC
+              else
+                errorModes.OLD_RUSTC
         else
-          false
+          throw 'rustc returned inapplicable result: ' + stdout
 
   locateCargo: (curDir) =>
     root_dir = if /^win/.test process.platform then /^.:\\$/ else /^\/$/
@@ -296,24 +176,4 @@ class LinterRust
       directory = path.resolve path.join(directory, '..')
     return false
 
-  buildCargoPath: (cargoPath) =>
-    @usingMultitoolForClippy().then (canUseMultirust) =>
-      if @cargoCommand == 'clippy' and canUseMultirust.result
-        [canUseMultirust.tool, 'run', 'nightly', 'cargo']
-      else
-        [cargoPath]
-
-  usingMultitoolForClippy: () =>
-    # Try to use rustup
-    sb_exec.exec 'rustup', ['--version'], {ignoreExitCode: true}
-      .then ->
-        result: true, tool: 'rustup'
-      .catch ->
-        # Try to use odler multirust at least
-        sb_exec.exec 'multirust', ['--version'], {ignoreExitCode: true}
-          .then ->
-            result: true, tool: 'multirust'
-          .catch ->
-            result: false
-
 module.exports = LinterRust