Add some helpers for doing simple compilations.

Port the file tests and the "xfail" missing import test to use them.

Also: current directory is no longer in the search path by default,
but compile_file() adds the given file's containing directory.

5 files changed, 64 insertions, 11 deletions

diff --git a/conftest.py b/conftest.py
index 014b4d8..0a81986 100644
--- a/conftest.py
+++ b/conftest.py
@@ -8,7 +8,12 @@ import logging
 import pytest
 
 import scss
+from scss.compiler import compile_file
 import scss.config
+from scss.extension.core import CoreExtension
+from scss.extension.extra import ExtraExtension
+from scss.extension.fonts import FontsExtension
+from scss.extension.compass import CompassExtension
 
 try:
     import fontforge
@@ -97,22 +102,26 @@ class SassItem(pytest.Item):
         scss_file = self.fspath
         css_file = scss_file.new(ext='css')
 
-        with scss_file.open('rb') as fh:
-            source = fh.read()
         with css_file.open('rb') as fh:
             # Output is Unicode, so decode this here
             expected = fh.read().decode('utf8')
 
         scss.config.STATIC_ROOT = str(scss_file.dirpath('static'))
 
-        compiler = scss.Scss(
-            scss_opts=dict(style='expanded'),
-            search_paths=[
+        actual = compile_file(
+            str(scss_file),
+            output_style='expanded',
+            search_path=[
                 str(scss_file.dirpath('include')),
                 str(scss_file.dirname),
             ],
+            extensions=[
+                CoreExtension,
+                ExtraExtension,
+                FontsExtension,
+                CompassExtension,
+            ],
         )
-        actual = compiler.compile(source)
 
         # Normalize leading and trailing newlines
         actual = actual.strip('\n')
diff --git a/scss/compiler.py b/scss/compiler.py
index ac9dea7..dceacef 100644
--- a/scss/compiler.py
+++ b/scss/compiler.py
@@ -85,15 +85,12 @@ def warn_deprecated(rule, message):
     )
 
 
-# TODO it's probably still kind of weird to go Compiler().compile('a/b/c') and
-# not have stuff in a/b/ importable.  maybe need a top-level compile_sass()
-# function that takes a single file?  (compile_file?  compile_string?)
 class Compiler(object):
     """A Sass compiler.  Stores settings and knows how to fire off a
     compilation.  Main entry point into compiling Sass.
     """
     def __init__(
-            self, root='', search_path=('',),
+            self, root='', search_path=(),
             namespace=None, extensions=(CoreExtension,),
             output_style='nested', generate_source_map=False,
             live_errors=False, warn_unused_imports=False,
@@ -180,10 +177,49 @@ class Compiler(object):
     def compile(self, *filenames):
         compilation = self.make_compilation()
         for filename in filenames:
+            # TODO maybe SourceFile should not be exposed to the end user, and
+            # instead Compilation should have methods for add_string etc. that
+            # can call normalize_path.
+            # TODO it's not possible to inject custom files into the
+            # /compiler/ as persistent across compiles, nor to provide "fake"
+            # imports.  do we want the former?  is the latter better suited to
+            # an extension?
             source = SourceFile.from_filename(self.normalize_path(filename))
             compilation.add_source(source)
         return self.call_and_catch_errors(compilation.run)
 
+    def compile_string(self, string):
+        source = SourceFile.from_string(string)
+        compilation = self.make_compilation()
+        compilation.add_source(source)
+        return self.call_and_catch_errors(compilation.run)
+
+
+def compile_file(filename, compiler_class=Compiler, **kwargs):
+    """Compile a single file, and return a string of CSS.
+
+    Keyword arguments are passed along to the underlying `Compiler`.
+
+    Note that the search path is set to the file's containing directory by
+    default, unless you explicitly pass a ``search_path`` kwarg.
+    """
+    if 'search_path' not in kwargs:
+        kwargs['search_path'] = [
+            os.path.abspath(os.path.dirname(filename)),
+        ]
+
+    compiler = compiler_class(**kwargs)
+    return compiler.compile(filename)
+
+
+def compile_string(string, compiler_class=Compiler, **kwargs):
+    """Compile a single string, and return a string of CSS.
+
+    Keyword arguments are passed along to the underlying `Compiler`.
+    """
+    compiler = compiler_class(**kwargs)
+    return compiler.compile_string(string)
+
 
 class Compilation(object):
     """A single run of a compiler."""
diff --git a/scss/tests/files/xfail/missing-import.css b/scss/tests/files/xfail/missing-import.css
deleted file mode 100644
index e69de29..0000000
--- a/scss/tests/files/xfail/missing-import.css
+++ /dev/null
diff --git a/scss/tests/files/xfail/missing-import.scss b/scss/tests/files/xfail/missing-import.scss
deleted file mode 100644
index c10a6bb..0000000
--- a/scss/tests/files/xfail/missing-import.scss
+++ /dev/null
@@ -1 +0,0 @@
-@import "missing-file";
diff --git a/scss/tests/test_misc.py b/scss/tests/test_misc.py
index adcb893..767a319 100644
--- a/scss/tests/test_misc.py
+++ b/scss/tests/test_misc.py
@@ -4,6 +4,8 @@ own files, maybe.
 """
 
 from scss import Scss
+from scss.compiler import compile_string
+from scss.errors import SassImportError
 
 
 def test_super_selector():
@@ -107,3 +109,10 @@ def test_unicode_files():
     output = compiler.compile(unicode_input)
 
     assert output == unicode_input
+
+
+def test_missing_import():
+    with pytest.raises(SassImportError):
+        compile_string("""
+            @import "bogus-file";
+        """)