Is a directory the project root?
Objects of the root_criterion class decide if a
given directory is a project root.
root_criterion(testfun, desc, subdir = NULL) is_root_criterion(x) as_root_criterion(x) ## S3 method for class 'character' as_root_criterion(x) ## S3 method for class 'root_criterion' as_root_criterion(x) ## S3 method for class 'root_criterion' x | y has_file(filepath, contents = NULL, n = -1L, fixed = FALSE) has_dir(filepath) has_file_pattern(pattern, contents = NULL, n = -1L, fixed = FALSE) has_basename(basename, subdir = NULL)
testfun |
|
desc |
|
subdir |
|
x |
|
y |
|
filepath |
|
contents, fixed |
|
n |
|
pattern |
|
basename |
|
Construct criteria using root_criterion in a very general fashion
by specifying a function with a path argument, and a description.
The as_root_criterion() function accepts objects of class
root_criterion, and character values; the latter will be
converted to criteria using has_file.
Root criteria can be combined with the | operator. The result is a
composite root criterion that requires either of the original criteria to
match.
The has_file() function constructs a criterion that checks for the
existence of a specific file (which itself can be in a subdirectory of the
root) with specific contents.
The has_dir() function constructs a criterion that checks for the
existence of a specific directory.
The has_file_pattern() function constructs a criterion that checks for the
existence of a file that matches a pattern, with specific contents.
The has_basename() function constructs a criterion that checks if the
base::basename() of the root directory has a specific name,
with support for case-insensitive file systems.
An S3 object of class root_criterion wit the following members:
testfunThe testfun argument
descThe desc argument
subdirThe subdir argument
find_fileA function with ... and path arguments
that returns a path relative to the root,
as specified by this criterion.
The optional path argument specifies the starting directory,
which defaults to ".".
The function forwards to find_root_file(),
which passes ... directly to file.path()
if the first argument is an absolute path.
make_fix_fileA function with a path argument that
returns a function that finds paths relative to the root. For a
criterion cr, the result of cr$make_fix_file(".")(...)
is identical to cr$find_file(...). The function created by
make_fix_file() can be saved to a variable to be more independent
of the current working directory.
root_criterion(function(path) file.exists(file.path(path, "somefile")), "has somefile")
has_file("DESCRIPTION")
is_r_package
is_r_package$find_file
## Not run:
is_r_package$make_fix_file(".")
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