-spec analyse() -> {result, analyse_ok(), analyse_fail()} | {error, not_main_node}.

Equivalent to analyse('_', coverage, function).

-spec analyse(Analysis) -> {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when Analysis :: analysis();
       (Level) -> {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when Level :: level();
       (Modules) -> OneResult | {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when Modules :: modules(), OneResult :: one_result().

Analyzes one or more modules as specified by Arg.

If Arg is one of the values in analysis(), this call is equivalent to analyse('_', Arg, function).

If Arg is one of the values in level(), this call is equivalent to analyse('_', coverage, Arg).

Otherwise Arg is assumed to be a module name, and this call is equivalent to analyse(Arg, coverage, function).

Note

To analyze a module whose name overlaps with one the values in analysis() or level(), the module name has to be in a list. For example, to analyze a module named calls:

cover:analyse([calls]).

-spec analyse(Analysis, Level) -> {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when Analysis :: analysis(), Level :: level();
       (Modules, Analysis) ->
           OneResult | {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when Analysis :: analysis(), Modules :: modules(), OneResult :: one_result();
       (Modules, Level) ->
           OneResult | {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when Level :: level(), Modules :: modules(), OneResult :: one_result().

Analyzes one or more modules as specified by Arg1 and Arg2.

If Arg1 is one of the values in analysis() and Arg2 is one of the values in level(), this call is equivalent to analyse('_', Arg1, Arg2).

If Arg2 is one of the values in analysis(), Arg1 is assumed to be a module and this call is equivalent to analyse(Arg1, Arg2, function).

If Arg2 is one of the values in level(), Arg1 is assumed to be a module and this call is equivalent to analyse(Arg1, coverage, Arg2).

Note

To analyze a module whose name overlaps with one of the values in analysis(), the module name needs to be in a list. For example, to analyze a module named calls:

cover:analyse([calls], function).

-spec analyse(Modules, Analysis, Level) ->
           OneResult | {result, analyse_ok(), analyse_fail()} | {error, not_main_node}
           when
               Analysis :: analysis(),
               Level :: level(),
               Modules :: modules(),
               OneResult :: one_result().

Perform analysis of one or more cover-compiled modules, as specified by Analysis and Level, by examining the contents of the internal database.

If Modules is an atom (a single module), the return is OneResult, otherwise the return is {result, Ok, Fail}.

If Modules is atom '_', all modules that have data in the cover data table are analysed. Note that this includes both cover-compiled modules and imported modules.

If a given module is not cover-compiled, this is indicated by the error reason {not_cover_compiled, Module}.

-spec analyse_to_file() -> {result, analyse_file_ok(), analyse_file_fail()} | {error, not_main_node}.

Equivalent to analyse_to_file('_', []).

-spec analyse_to_file(Modules) ->
                   Answer |
                   {result, analyse_file_ok(), analyse_file_fail()} |
                   {error, not_main_node}
                   when Modules :: modules(), Answer :: analyse_answer();
               (Options) ->
                   {result, analyse_file_ok(), analyse_file_fail()} | {error, not_main_node}
                   when Options :: [analyse_option()].

If Arg is a list of analyse_option() options, this call is equivalent to analyse_to_file('_', Arg).

Otherwise Arg is assumed to be a module, and this call is equivalent to analyse_to_file(Arg, []).

Note

To analyze a module of the name html (which overlaps with an option in analyse_option()), it is necessary to use cover:analyse_to_file/2:

cover:analyse_to_file([html], []).

-spec analyse_to_file(Modules, Options) ->
                   Answer |
                   {result, analyse_file_ok(), analyse_file_fail()} |
                   {error, not_main_node}
                   when
                       Modules :: modules(),
                       Options :: [analyse_option()],
                       Answer :: analyse_answer().

Outputs copies of the source code for the given modules annotated with execution counts for each executable line.

The output file OutFile defaults to Module.COVER.out, and to Module.COVER.html if option html is used.

If Modules is an atom (one module), the return will be Answer, otherwise the return will be a list, {result, Ok, Fail}.

If Modules is '_', all modules that have data in the Cover data table are analysed. Note that this includes both cover-compiled modules and imported modules.

If a module is not cover-compiled, this is indicated by the error reason {not_cover_compiled, Module}.

If the source file and/or the output file cannot be opened using file:open/2, the function returns {error, {file, File, Reason}}, where File is the file name and Reason is the error reason.

If a module was cover compiled from the .beam file, that is, using compile_beam/1 or compile_beam_directory/0,1 , it is assumed that the source code can be found in one of the following locations:

• the same directory as the .beam file
• ../src relative to the directory with .beam file
• the source path in Module:module_info(compile), in which case two paths are examined:
  • first the one constructed by joining ../src and the tail of the compiled path below a trailing src component
  • the compiled path itself

If no source code is found, this is indicated by the error reason {no_source_code_found, Module}.

-spec async_analyse_to_file(Module) -> pid() when Module :: module().

Equivalent to async_analyse_to_file/3.

-spec async_analyse_to_file(Module, OutFile) -> pid()
                         when Module :: module(), OutFile :: file:filename();
                     (Module, Options) -> pid()
                         when Module :: module(), Options :: [Option], Option :: html.

Equivalent to async_analyse_to_file/3.

-spec async_analyse_to_file(Module, OutFile, Options) -> pid()
                         when
                             Module :: module(),
                             OutFile :: file:filename(),
                             Options :: [Option],
                             Option :: html.

This function works the same way as analyse_to_file/2 except that it is asynchronous instead of synchronous.

The spawned process will link with the caller when created. If an error of type analyse_rsn() occurs while doing the cover analysis the process will crash with the same error reason as analyse_to_file would return.

-spec compile(ModFiles) -> Result | [Result] when ModFiles :: mod_files(), Result :: compile_result().

Equivalent to compile_module(ModFiles, []).

-spec compile(ModFiles, Options) -> Result | [Result]
           when ModFiles :: mod_files(), Options :: [option()], Result :: compile_result().

Equivalent to compile_module(ModFile, Options).

-spec compile_beam(ModFiles) -> Result | [Result]
                when ModFiles :: beam_mod_files(), Result :: compile_beam_result().

Cover-compiles one or more modules based .beam files containing abstract code (option debug_info).

Cover-compiling from .beam files is faster than compiling from source and less hassle, because there is no need to supply options for include paths or macros. However, the existing .beam files must have been compiled with option debug_info so that they contain abstract code.

If abstract code is missing, the error reason {no_abstract_code, BeamFile} is returned. If the abstract code is encrypted, and no key is available for decrypting it, the error reason {encrypted_abstract_code, BeamFile} is returned.

If only the module name (that is, not the full name of the .beam file) is given to this function, the .beam file is found by calling code:which(Module). If no .beam file is found, the error reason non_existing is returned. If the module is already cover compiled with compile_beam/1, the .beam file will be picked from the same location as the first time it was compiled. If the module is already cover-compiled with compile_module/2, there is no way to find the correct .beam file, so the error reason {already_cover_compiled, no_beam_found, Module} is returned.

{error, BeamFile} is returned if the compiled code cannot be loaded on the node.

If a list of ModFiles is given as input, a list of Result will be returned. The order of the returned list is undefined.

-spec compile_beam_directory() -> [Result] | {error, Reason}
                          when Reason :: file_error(), Result :: compile_beam_result().

Equivalent to compile_beam_directory(".").

-spec compile_beam_directory(Dir) -> [Result] | {error, Reason}
                          when
                              Dir :: file:filename(),
                              Reason :: file_error(),
                              Result :: compile_beam_result().

Cover-compiles all .beam files in directory Dir in the same way as compile_beam/1.

This function returns a list of compile_beam_result() if successful. Otherwise, it returns {error, eacces} if the directory is not readable, and {error, enoent} if the directory does not exist.

-spec compile_directory() -> [Result] | {error, Reason}
                     when Reason :: file_error(), Result :: compile_result().

Equivalent to compile_directory(".", []).

-spec compile_directory(Dir) -> [Result] | {error, Reason}
                     when
                         Dir :: file:filename(),
                         Reason :: file_error(),
                         Result :: compile_result().

Equivalent to compile_directory(Dir, []).

-spec compile_directory(Dir, Options) -> [Result] | {error, Reason}
                     when
                         Dir :: file:filename(),
                         Options :: [option()],
                         Reason :: file_error(),
                         Result :: compile_result().

Compiles all modules (.erl files) in a directory Dir for Cover analysis the same way as compile_module/1,2 and returns a list of Result.

This function returns {error, eacces} if the directory is not readable or {error, enoent} if the directory does not exist.

-spec compile_module(ModFiles) -> Result | [Result]
                  when ModFiles :: mod_files(), Result :: compile_result().

Equivalent to compile_module(ModFile, []).

-spec compile_module(ModFiles, Options) -> Result | [Result]
                  when ModFiles :: mod_files(), Options :: [option()], Result :: compile_result().

Cover-compiles one or more modules.

The module is given by its module name Module or by its file name File.

The .erl extension can be omitted. If the module is not located in the current directory, the full path to it must be specified.

Options is a list of compiler options. Only options defining include file directories and macros are passed to compile:file/2; everything else is ignored.

If the module is successfully cover-compiled, the function returns {ok, Module}. Otherwise the function returns {error, File}. Errors and warnings are printed as they occur.

If a list of ModFiles is given as input, a list of Result will be returned. The order of the returned results in the list is undefined.

Note that the internal database is initialized during the compilation, which means that any previously collected coverage data for the module is lost.

-spec export(File) -> ok | {error, Reason} when File :: file:filename(), Reason :: export_reason().

Equivalent to export(File, '_').

-spec export(File, Module) -> ok | {error, Reason}
          when File :: file:filename(), Module :: module(), Reason :: export_reason().

Exports the current coverage data for Module to the file ExportFile.

It is recommended to name the ExportFile with the extension .coverdata.

If Module is '_', data for all cover-compiled or earlier imported modules is exported.

This function is useful if coverage data from different systems is to be merged.

See also import/1.

-spec flush(Nodes) -> ok | {error, not_main_node} when Nodes :: node() | [node()].

Fetches data from the Cover database on the remote nodes and stores it on the main node.

-spec import(ExportFile) -> ok | {error, Reason}
          when
              ExportFile :: file:filename(),
              Reason :: {cant_open_file, ExportFile, FileReason :: term()} | not_main_node.

Imports coverage data from the file ExportFile created with export/1,2.

Any analysis performed after this call will include the imported data.

Note that when compiling a module all existing coverage data is removed, including imported data. If a module is already compiled when data is imported, the imported data is added to the existing coverage data.

Coverage data from several export files can be imported into one system. The coverage data is then added up when analysing.

Coverage data for a module cannot be imported from the same file twice unless the module is first reset or compiled. The check is based on the filename, so you can easily fool the system by renaming your export file.

-spec imported() -> [file:filename()] | {error, not_main_node}.

Returns a list of all imported files.

-spec imported_modules() -> [module()] | {error, not_main_node}.

Returns a list of all modules for which there are imported data.

-spec is_compiled(Module) -> {file, File :: file:filename()} | false | {error, not_main_node}
               when Module :: module().

Returns {file, File} if the module Module is cover-compiled, or false otherwise.

File is the .erl file used by compile_module/1,2 or the .beam file used by compile_beam/1.

-spec local_only() -> ok | {error, too_late}.

Only support running Cover on the local node.

This function has to be called before any modules have been compiled or any nodes added. When running in this mode, modules will be cover-compiled in a more efficient way, but the resulting code will only work on the same node they were compiled on.

-spec modules() -> [module()] | {error, not_main_node}.

Returns a list with all modules that are currently cover-compiled.

-spec reset() -> ok | {error, not_main_node}.

Resets all coverage data for all cover-compiled modules in the Cover database on all nodes.

-spec reset(Module) -> ok | {error, not_main_node} | {error, {not_cover_compiled, Module}}
         when Module :: module().

Resets all coverage data for the cover-compiled module Module in the Cover database on all nodes.

If Module is not cover-compiled, the function returns {error, {not_cover_compiled, Module}}.

-spec start() -> {ok, pid()} | {error, Reason} when Reason :: {already_started, pid()} | term().

Starts the Cover server which owns the Cover internal database. This function is called automatically by the other functions in the module.

-spec start(Nodes) -> {ok, StartedNodes} | {error, not_main_node} | {error, local_only}
         when Nodes :: node() | [node()], StartedNodes :: [node()].

Starts a Cover server on the each of given nodes, and loads all cover compiled modules.

This call will fail if cover:local_only/0 has been called.

-spec stop() -> ok | {error, not_main_node}.

Stops the Cover server and unloads all cover-compiled code.

-spec stop(Nodes) -> ok | {error, not_main_node} when Nodes :: node() | [node()].

Stops the Cover server and unloads all cover-compiled code on the given nodes.

Data stored in the Cover database on the remote nodes is fetched and stored on the main node.

-spec which_nodes() -> [node()].

Returns a list with all nodes that are part of the coverage analysis.

Note that the current node is not included, because it is always part of the analysis.