Codegen: make missing codeql error clearer

misc/codegen/generators/qlgen.py

@@ -24,6 +24,7 @@
 import logging
 import pathlib
 import re
+import shutil
 import subprocess
 import typing
 import itertools
@@ -257,6 +258,15 @@ def format(codeql, files):
     if not ql_files:
         return
     format_cmd = [codeql, "query", "format", "--in-place", "--"] + ql_files
+    if "/" in codeql:
+        if not pathlib.Path(codeql).exists():
+            raise FormatError(f"Provided CodeQL binary `{codeql}` does not exist")
+    else:
+        codeql_path = shutil.which(codeql)
+        if not codeql_path:
+            raise FormatError(
+                f"`{codeql}` not found in PATH. Either install it, or pass `-- --codeql-binary` with a full path")
+        codeql = codeql_path
     res = subprocess.run(format_cmd, stderr=subprocess.PIPE, text=True)
     if res.returncode:
         for line in res.stderr.splitlines():

misc/codegen/test/test_qlgen.py

@@ -52,6 +52,8 @@ def qlgen_opts(opts):
     opts.ql_format = True
     opts.root_dir = paths.root_dir
     opts.force = False
+    opts.codeql_binary = "./my_fake_codeql"
+    pathlib.Path(opts.codeql_binary).touch()
     return opts
 
 
@@ -499,7 +501,6 @@ def test_class_dir_imports(generate_import_list):
 
 
 def test_format(opts, generate, render_manager, run_mock):
-    opts.codeql_binary = "my_fake_codeql"
     run_mock.return_value.stderr = "some\nlines\n"
     render_manager.written = [
         pathlib.Path("x", "foo.ql"),
@@ -508,13 +509,12 @@ def test_format(opts, generate, render_manager, run_mock):
     ]
     generate([schema.Class('A')])
     assert run_mock.mock_calls == [
-        mock.call(["my_fake_codeql", "query", "format", "--in-place", "--", "x/foo.ql", "bar.qll"],
+        mock.call([opts.codeql_binary, "query", "format", "--in-place", "--", "x/foo.ql", "bar.qll"],
                   stderr=subprocess.PIPE, text=True),
     ]
 
 
 def test_format_error(opts, generate, render_manager, run_mock):
-    opts.codeql_binary = "my_fake_codeql"
     run_mock.return_value.stderr = "some\nlines\n"
     run_mock.return_value.returncode = 1
     render_manager.written = [
@@ -526,6 +526,24 @@ def test_format_error(opts, generate, render_manager, run_mock):
         generate([schema.Class('A')])
 
 
+def test_format_no_codeql(opts, generate, render_manager, run_mock):
+    pathlib.Path(opts.codeql_binary).unlink()
+    render_manager.written = [
+        pathlib.Path("bar.qll"),
+    ]
+    with pytest.raises(qlgen.FormatError):
+        generate([schema.Class('A')])
+
+
+def test_format_no_codeql_in_path(opts, generate, render_manager, run_mock):
+    opts.codeql_binary = "my_fake_codeql"
+    render_manager.written = [
+        pathlib.Path("bar.qll"),
+    ]
+    with pytest.raises(qlgen.FormatError):
+        generate([schema.Class('A')])
+
+
 @pytest.mark.parametrize("force", [False, True])
 def test_manage_parameters(opts, generate, renderer, force):
     opts.force = force