Bibliothecary::FileParsingError: add error location to error, and exp…

…ose via create_error_analysis (#582)

* Add file location data to FileParsingError messages

e.g. before:
pyproject.toml: no implicit conversion of Hash into Array

e.g. after:
pyproject.toml: no implicit conversion of Hash into Array (parsers/pypi.rb:109:in `+')

* Add specs

* Add an error_message field to the error instead of inside the msg

* 8.7.3

lib/bibliothecary/analyser.rb

@@ -4,14 +4,15 @@
 
 module Bibliothecary
   module Analyser
-    def self.create_error_analysis(platform_name, relative_path, kind, message)
+    def self.create_error_analysis(platform_name, relative_path, kind, message, location=nil)
       {
         platform: platform_name,
         path: relative_path,
         dependencies: nil,
         kind: kind,
         success: false,
-        error_message: message
+        error_message: message,
+        error_location: location,
       }
     end
 

lib/bibliothecary/analyser/analysis.rb

@@ -42,7 +42,7 @@ def analyse_contents_from_info(info, options: {})
 
         dependencies_to_analysis(info, kind, dependencies)
       rescue Bibliothecary::FileParsingError => e
-        Bibliothecary::Analyser::create_error_analysis(platform_name, info.relative_path, kind, e.message)
+        Bibliothecary::Analyser::create_error_analysis(platform_name, info.relative_path, kind, e.message, e.location)
       end
       alias analyze_contents_from_info analyse_contents_from_info
 
@@ -84,7 +84,10 @@ def parse_file(filename, contents, options: {})
 
       rescue Exception => e # default is StandardError but C bindings throw Exceptions
         # the C xml parser also puts a newline at the end of the message
-        raise Bibliothecary::FileParsingError.new(e.message.strip, filename)
+        location = e.backtrace_locations[0]
+          .to_s
+          .then { |l| l =~ /bibliothecary\// ? l.split("bibliothecary/").last : l.split("gems/").last }
+        raise Bibliothecary::FileParsingError.new(e.message.strip, filename, location)
       end
 
       private

lib/bibliothecary/exceptions.rb

@@ -8,9 +8,10 @@ def initialize(msg, code)
   end
 
   class FileParsingError < StandardError
-    attr_accessor :filename
-    def initialize(msg, filename)
+    attr_accessor :filename, :location
+    def initialize(msg, filename, location=nil)
       @filename = filename
+      @location = location # source code location of the error, e.g. "lib/hi.rb:34"
       msg = "#{filename}: #{msg}" unless msg.include?(filename)
       super("#{msg}")
     end

lib/bibliothecary/version.rb

@@ -1,3 +1,3 @@
 module Bibliothecary
-  VERSION = "8.7.2"
+  VERSION = "8.7.3"
 end

spec/bibliothecary_spec.rb

@@ -285,7 +285,8 @@
         dependencies: [],
         kind: "unknown",
         success: false,
-        error_message: "No parser for this file type" }
+        error_message: "No parser for this file type",
+        error_location: nil }
       ])
 
     Bibliothecary.reset

spec/parsers/maven_spec.rb

@@ -306,7 +306,8 @@
       dependencies: nil,
       kind: 'lockfile',
       success: false,
-      error_message: "missing_info.xml: ivy-report document lacks <info> element"
+      error_message: "missing_info.xml: ivy-report document lacks <info> element",
+      error_location: "parsers/maven.rb:134:in `parse_ivy_report'"
     })
   end
 

spec/parsers/npm_spec.rb

@@ -152,7 +152,8 @@
       dependencies: nil,
       kind: 'manifest',
       success: false,
-      error_message: "package.json: appears to be a lockfile rather than manifest format"
+      error_message: "package.json: appears to be a lockfile rather than manifest format",
+      error_location: "parsers/npm.rb:97:in `parse_manifest'"
     })
   end