Merge pull request #745 from PiotrCzapla/main

refactor tools: centralize error handling with explain_exc and ensure

Author: jph00

fastcore/_modidx.py

@@ -589,6 +589,8 @@
                                'fastcore.test.test_warns': ('test.html#test_warns', 'fastcore/test.py')},
             'fastcore.tools': { 'fastcore.tools._fmt_path': ('tools.html#_fmt_path', 'fastcore/tools.py'),
                                 'fastcore.tools.create': ('tools.html#create', 'fastcore/tools.py'),
+                                'fastcore.tools.ensure': ('tools.html#ensure', 'fastcore/tools.py'),
+                                'fastcore.tools.explain_exc': ('tools.html#explain_exc', 'fastcore/tools.py'),
                                 'fastcore.tools.get_callable': ('tools.html#get_callable', 'fastcore/tools.py'),
                                 'fastcore.tools.insert': ('tools.html#insert', 'fastcore/tools.py'),
                                 'fastcore.tools.move_lines': ('tools.html#move_lines', 'fastcore/tools.py'),

fastcore/tools.py

@@ -2,27 +2,51 @@
 
 # AUTOGENERATED! DO NOT EDIT! File to edit: ../nbs/12_tools.ipynb.
 
-# %% auto #0
-__all__ = ['run_cmd', 'rg', 'sed', 'valid_path', 'view', 'create', 'insert', 'str_replace', 'strs_replace', 'replace_lines',
-           'move_lines', 'get_callable']
+# %% auto 0
+__all__ = ['explain_exc', 'ensure', 'valid_path', 'run_cmd', 'rg', 'sed', 'view', 'create', 'insert', 'str_replace',
+           'strs_replace', 'replace_lines', 'move_lines', 'get_callable']
 
 # %% ../nbs/12_tools.ipynb #578246d2
 from .imports import *
+from .xtras import truncstr
 from shlex import split
 from subprocess import run, DEVNULL
 
-# %% ../nbs/12_tools.ipynb #1182336d
+# %% ../nbs/12_tools.ipynb
+def explain_exc(task=''):
+    """Convert an current exception to  an LLM friendly error message."""
+    try: raise sys.exc_info()[1]
+    except (AssertionError, ZeroDivisionError, ValueError, FileNotFoundError) as e:
+        return f"Error: {e}"
+    except Exception as e: return f"Error {task}: {repr(e)}"
+
+
+# %% ../nbs/12_tools.ipynb
+def ensure(b: bool, msg:str=""):
+    "Works like assert b, msg but raise ValueError and is not disabled when run with python -O"
+    if not b: raise ValueError(msg)
+
+
+# %% ../nbs/12_tools.ipynb
+def valid_path(path:str, must_exist:bool=True) -> Path:
+    'Return expanded/resolved Path, raising FileNotFoundError if must_exist and missing'
+    p = Path(path).expanduser().resolve()
+    if must_exist and not p.exists(): raise FileNotFoundError(f'File not found: {p}')
+    return p
+
+# %% ../nbs/12_tools.ipynb
 def run_cmd(
     cmd:str, # The command name to run
     argstr:str='', # All args to the command, will be split with shlex
     disallow_re:str=None, # optional regex which, if matched on argstr, will disallow the command
     allow_re:str=None # optional regex which, if not matched on argstr, will disallow the command
 ):
     "Run `cmd` passing split `argstr`, optionally checking for allowed argstr"
-    if disallow_re and re.search(disallow_re, argstr): return 'Error: args disallowed'
-    if allow_re    and re.search(   allow_re, argstr): return 'Error: args not allowed'
-    try: outp = run([cmd] + split(argstr), text=True, stdin=DEVNULL, capture_output=True)
-    except Exception as e: return f'Error running cmd: {str(e)}'
+    try:
+        ensure(not (disallow_re and re.search(disallow_re, argstr)), 'args disallowed')
+        ensure(not (allow_re    and re.search(   allow_re, argstr)), 'args not allowed')
+        outp = run([cmd] + split(argstr), text=True, stdin=DEVNULL, capture_output=True)
+    except: return explain_exc(f'running cmd')
     res = outp.stdout
     if res and outp.stderr: res += '\n'
     return res + outp.stderr
@@ -45,15 +69,8 @@ def sed(
     "Run the `sed` command with the args in `argstr` (e.g for reading a section of a file)"
     return run_cmd('sed', argstr, allow_re=allow_re, disallow_re=disallow_re)
 
-# %% ../nbs/12_tools.ipynb #5dd1aaf3
-def valid_path(path:str, must_exist:bool=True) -> Path:
-    'Return expanded/resolved Path, raising FileNotFoundError if must_exist and missing'
-    p = Path(path).expanduser().resolve()
-    if must_exist and not p.exists(): raise FileNotFoundError(f'File not found: {p}')
-    return p
-
-# %% ../nbs/12_tools.ipynb #b718d65b
-def _fmt_path(f, p, skip_folders=()):
+# %% ../nbs/12_tools.ipynb
+def _fmt_path(f, p):
     'Format path with emoji for dirs/symlinks or size for files'
     parts = f.relative_to(p).parts
     if any(part.startswith('.') for part in parts): return None
@@ -80,13 +97,13 @@ def view(
         s, e = 1, len(lines)
         if view_range:
             s,e = view_range
-            if not (1<=s<=len(lines)): return f'Error: Invalid start line {s}'
-            if e!=-1 and not (s<=e<= len(lines)): return f'Error: Invalid end line {e}'
+            ensure(1<=s<=len(lines), f'Invalid start line {s}')
+            ensure(e==-1 or s<=e<=len(lines), f'Invalid end line {e}')
             lines = lines[s-1:None if e==-1 else e]
         if nums: lines = [f'{i+s:6d} │ {l}' for i, l in enumerate(lines)]
         content = '\n'.join(lines)
         return f'{header}\n{content}' if header else content
-    except Exception as e: return f'Error viewing: {str(e)}'
+    except: return explain_exc('viewing')
 
 # %% ../nbs/12_tools.ipynb #36f58e38
 def create(
@@ -102,7 +119,7 @@ def create(
         p.parent.mkdir(parents=True, exist_ok=True)
         p.write_text(file_text)
         return f'Created file {p}.'
-    except Exception as e: return f'Error creating file: {str(e)}'
+    except: return explain_exc('creating file')
 
 # %% ../nbs/12_tools.ipynb #434147ef
 def insert(
@@ -114,12 +131,12 @@ def insert(
     try:
         p = valid_path(path)
         content = p.read_text().splitlines()
-        if not (0 <= insert_line <= len(content)): return f'Error: Invalid line number {insert_line}'
+        ensure(0<=insert_line<=len(content), f'Invalid line number {insert_line}')
         content.insert(insert_line, new_str)
         new_content = '\n'.join(content)
         p.write_text(new_content)
         return f'Inserted text at line {insert_line} in {p}'
-    except Exception as e: return f'Error inserting text: {str(e)}'
+    except: return explain_exc('inserting text')
 
 # %% ../nbs/12_tools.ipynb #9272ff7d
 def str_replace(
@@ -132,12 +149,12 @@ def str_replace(
         p = valid_path(path)
         content = p.read_text()
         count = content.count(old_str)
-        if count == 0: return 'Error: Text not found in file'
-        if count > 1: return f'Error: Multiple matches found ({count})'
+        if count == 0: return f'Error: Text "{truncstr(old_str, 10)}" not found in file'
+        if count > 1: return f'Error: Multiple matches found ({count}) of "{truncstr(old_str, 10)}"'
         new_content = content.replace(old_str, new_str, 1)
         p.write_text(new_content)
         return f'Replaced text in {p}'
-    except Exception as e: return f'Error replacing text: {str(e)}'
+    except: return explain_exc('replacing text')
 
 # %% ../nbs/12_tools.ipynb #eb907119
 def strs_replace(
@@ -164,7 +181,7 @@ def replace_lines(
         content[start_line-1:end_line] = [new_content]
         p.write_text(''.join(content))
         return f"Replaced lines {start_line} to {end_line}."
-    except Exception as e: return f'Error replacing lines: {str(e)}'
+    except: return explain_exc('replacing lines')
 
 # %% ../nbs/12_tools.ipynb #b136abf8
 def move_lines(
@@ -177,9 +194,9 @@ def move_lines(
     try:
         p = valid_path(path)
         lines = p.read_text().splitlines()
-        assert 1 <= start_line <= end_line <= len(lines), f"Invalid range {start_line}-{end_line}"
-        assert 1 <= dest_line <= len(lines) + 1, f"Invalid destination {dest_line}"
-        assert not(start_line <= dest_line <= end_line + 1), "Destination within source range"
+        ensure(1 <= start_line <= end_line <= len(lines), f"Invalid range {start_line}-{end_line}")
+        ensure(1 <= dest_line <= len(lines) + 1, f"Invalid destination {dest_line}")
+        ensure(not(start_line <= dest_line <= end_line + 1), "Destination within source range")
 
         chunk = lines[start_line-1:end_line]
         del lines[start_line-1:end_line]
@@ -188,7 +205,7 @@ def move_lines(
         lines[dest_line-1:dest_line-1] = chunk
         p.write_text('\n'.join(lines) + '\n')
         return f"Moved lines {start_line}-{end_line} to line {dest_line}"
-    except Exception as e: return f'Error: {str(e)}'
+    except: return explain_exc()
 
 # %% ../nbs/12_tools.ipynb #fc53b116
 def get_callable():