path / impact: a file:line outside the file is refused with the file's length

plugins/axiomcode/skills/axiomcode/scripts/axiomcode-path

@@ -319,6 +319,11 @@ class G:
                 if p == root or p.startswith(root.rstrip('/') + '/'):
                     return os.path.relpath(p, root).replace(os.sep, '/'), False
         return f.lstrip('/'), True
+    def file_lines(self, f):
+        """how many lines the indexed file `f` has on disk, or None when it cannot be read there"""
+        try:
+            with open(os.path.join(self.repo, f), 'rb') as h: return len(h.read().splitlines())
+        except OSError: return None
     def _resolve(self, sel, fragment=False):
         s = sel.strip().strip('`"\'')
         # file:line, or file:line:col as a stack trace prints it — the column never changes which callable spans the line
@@ -340,6 +345,12 @@ class G:
                 if len(files) > 12: rows.append(f"  … +{len(files) - 12} more")
                 die(f"'{m.group(1)}' matches {len(files)} indexed files — give enough of the path to name one:\n" + '\n'.join(rows))
             if files: f = files[0]
+            # A LINE OUTSIDE THE FILE IS REFUSED (#1601). Line 0, or a line past the end — a number copied before the file
+            # was edited, or from an old stack trace — spans no callable, so it fell through to the module node and was
+            # answered as the file's top-level code, as if that line existed. The file on disk is what the reader sees.
+            if ln < 1: die(f"line {ln} is not in {f}: lines are numbered from 1")
+            n = self.file_lines(f) if files else None
+            if n is not None and ln > n: die(f"{f} has {n} line{'' if n == 1 else 's'}; line {ln} is not in it")
             # the smallest callable(s) spanning the line — several when they share it (`class Item { run(){} tag(){} }`);
             # top-level code belongs to the file's module node, which is a caller like any other
             r = self.q("SELECT id, end_line - line AS span FROM symbols WHERE file = ? AND line <= ? AND end_line >= ? AND method_id IS NOT NULL AND kind <> 'module' ORDER BY span", f, ln, ln)

tests/cases/javascript/fileline-line-outside-file/case.json

@@ -0,0 +1,42 @@
+{"lang": "javascript",
+ "checks": [
+  {"why": "a line past the end of the file is refused with the file's length, not answered as its top-level code (#1601)",
+   "run": ["impact", "src/services/userService.js:99"],
+   "expect_error": true,
+   "want": ["src/services/userService.js has 4 lines; line 99 is not in it"],
+   "avoid": ["<module>"]},
+  {"why": "line 0 is refused too",
+   "run": ["impact", "src/services/userService.js:0"],
+   "expect_error": true,
+   "want": ["line 0 is not in src/services/userService.js"],
+   "avoid": ["<module>"]},
+  {"why": "the same through path",
+   "run": ["path", "*", "src/services/userService.js:0"],
+   "expect_error": true,
+   "want": ["line 0 is not in src/services/userService.js"],
+   "avoid": ["0 method(s)"]},
+  {"why": "the line just past the end, through path, with a partial undotted file name",
+   "run": ["path", "*", "services/userService.js:5"],
+   "expect_error": true,
+   "want": ["src/services/userService.js has 4 lines; line 5 is not in it"],
+   "avoid": ["0 method(s)"]},
+  {"why": "a file with no newline at its end: the line after its last is refused",
+   "run": ["impact", "app.js:3"],
+   "expect_error": true,
+   "want": ["src/app.js has 2 lines; line 3 is not in it"]},
+  {"why": "control: the last line of a file with no newline at its end is still its top-level code",
+   "run": ["impact", "src/app.js:2"],
+   "want": ["app.<module> (at src/app.js:2)"],
+   "avoid": ["is not in it"]},
+  {"why": "control: the last line, top-level code, still answers as the module",
+   "run": ["impact", "src/services/userService.js:4"],
+   "want": ["userService.<module> (at src/services/userService.js:4)"],
+   "avoid": ["is not in it"]},
+  {"why": "control: a line inside a function still answers for that function, with its caller",
+   "run": ["path", "*", "src/services/userService.js:2"],
+   "want": ["getUser"],
+   "avoid": ["is not in it"]},
+  {"why": "control: a file the index does not hold is still refused as before",
+   "run": ["impact", "zzz/userService.js:99"],
+   "expect_error": true,
+   "want": ["no callable spans zzz/userService.js:99"]}]}

tests/cases/javascript/fileline-line-outside-file/src/app.js

@@ -0,0 +1,2 @@
+const { getUser } = require('./services/userService');
+getUser(1);

tests/cases/javascript/fileline-line-outside-file/src/db.js

@@ -0,0 +1 @@
+exports.find = function (id) { return { id }; };

tests/cases/javascript/fileline-line-outside-file/src/services/userService.js

@@ -0,0 +1,4 @@
+const db = require('../db');
+function getUser(id) { return db.find(id); }
+module.exports = { getUser };
+// last line