chore: one-liner cap 8 MiB, review at 3 MiB

The SHA-256 pin already refuses any changed byte: the cap in install.sh
and install.ps1 only stops a sign-in portal's page before it is hashed,
so it can be generous. The size test now fails once install.py passes
3 MiB, so its growth is looked at, and checks both bootstraps accept the
same 8 MiB. The separate size test of the earlier commit is folded into
the one test_install.py already had.

install.ps1

@@ -17,7 +17,9 @@
     # the site's build rewrites this line there (scripts/sitebootstrap.py).
     $mismatchAdvice = "The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
     $defaultInstallSha256 = "eb617bc1d0a220cc887e7763611a95cac9d3abd33acc1f115f7c048e51f218c7"
-    $maximumInstallerBytes = 2MB
+    # The pin above refuses any changed byte: this cap only stops a body that
+    # cannot be the installer (a sign-in portal's page) before it is hashed.
+    $maximumInstallerBytes = 8MB
     $installerExit = 0
     $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }
     $temporary = $null

install.sh

@@ -24,7 +24,9 @@ DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/ins
 # build rewrites this line there (scripts/sitebootstrap.py).
 MISMATCH_ADVICE="The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
 DEFAULT_INSTALL_SHA256="eb617bc1d0a220cc887e7763611a95cac9d3abd33acc1f115f7c048e51f218c7"
-MAX_INSTALLER_BYTES=2097152
+# The pin above refuses any changed byte: this cap only stops a body that
+# cannot be the installer (a sign-in portal's page) before it is hashed.
+MAX_INSTALLER_BYTES=8388608
 
 cleanup() {
   if [ -n "$TEMP_INSTALLER" ] && [ -f "$TEMP_INSTALLER" ]; then

tests/test_install.py

@@ -4799,9 +4799,13 @@ class TheBoardSystemsAreNamedFromTheCode(unittest.TestCase):
 
 
 class TheInstallerFitsTheOneLiners(unittest.TestCase):
-    """install.sh and install.ps1 refuse an installer over 2 MiB, and
-    install.py grew from 596 KB to 1.1 MB in twelve days with nothing
-    holding it under that: past it, every one-line install would stop."""
+    """install.sh and install.ps1 refuse an installer over their cap, 8 MiB:
+    the SHA-256 pin refuses any changed byte, and the cap only stops a page
+    served in its place. install.py grew from 596 KB to 1.1 MB in twelve
+    days: past REVIEW_BYTES its growth is looked at before it goes on."""
+
+    # The size past which install.py's growth is reviewed, well below the cap.
+    REVIEW_BYTES = 3 * 1024 ** 2
 
     def _caps(self) -> dict[str, int]:
         import re
@@ -4813,14 +4817,16 @@ class TheInstallerFitsTheOneLiners(unittest.TestCase):
         return {"install.sh": int(re.search(r"^MAX_INSTALLER_BYTES=(\d+)$", shell, re.M)[1]),
                 "install.ps1": int(number) * units[unit or ""]}
 
-    def test_a_quarter_of_each_cap_stays_free(self):
+    def test_both_one_liners_accept_the_same_size(self):
+        self.assertEqual(set(self._caps().values()), {8 * 1024 ** 2})
+
+    def test_install_py_stays_below_the_review_size(self):
         size = (REPO_ROOT / "install.py").stat().st_size
-        for script, cap in self._caps().items():
-            with self.subTest(script=script):
-                self.assertLessEqual(
-                    size, cap * 3 // 4,
-                    f"install.py is {size} bytes, past three quarters of the {cap} {script} "
-                    "accepts: shrink it or raise the cap in both one-liners")
+        self.assertLess(self.REVIEW_BYTES, min(self._caps().values()))
+        self.assertLess(
+            size, self.REVIEW_BYTES,
+            f"install.py is {size} bytes, past the {self.REVIEW_BYTES} that call for a "
+            "look at its growth: shrink it, or raise REVIEW_BYTES once reviewed")
 
     def test_the_refusal_names_a_cause_and_a_way_out(self):
         for script in ("install.sh", "install.ps1"):

tests/test_installer_size.py

@@ -1,53 +0,0 @@
-"""install.py stays under the size the one-liners accept.
-
-install.sh refuses an installer above MAX_INSTALLER_BYTES and install.ps1
-above $maximumInstallerBytes: past them every curl | sh and irm | iex
-stops before the first file. This test fails while there is still room,
-so the cap is raised, or the installer made smaller, before a release.
-"""
-
-from __future__ import annotations
-
-import tests  # noqa: F401  offline, scratch under tmp/, the suite's own cache
-
-import re
-import unittest
-from pathlib import Path
-
-REPO_ROOT = Path(__file__).resolve().parent.parent
-
-# The share of the cap install.py may use: 1.9 MiB of 2 MiB. Raising the
-# cap in both bootstraps raises the alert with it.
-ALERT_SHARE = 0.95
-
-_UNITS = {"": 1, "KB": 1024, "MB": 1024 ** 2, "GB": 1024 ** 3}
-
-
-def shell_cap() -> int:
-    text = (REPO_ROOT / "install.sh").read_text(encoding="utf-8")
-    return int(re.search(r"^MAX_INSTALLER_BYTES=(\d+)$", text, re.MULTILINE).group(1))
-
-
-def powershell_cap() -> int:
-    text = (REPO_ROOT / "install.ps1").read_text(encoding="utf-8")
-    found = re.search(r"\$maximumInstallerBytes\s*=\s*(\d+)\s*(KB|MB|GB)?\b", text)
-    return int(found.group(1)) * _UNITS[found.group(2) or ""]
-
-
-class InstallerFitsTheOneLiners(unittest.TestCase):
-    def test_both_bootstraps_accept_the_same_size(self):
-        self.assertEqual(shell_cap(), powershell_cap())
-
-    def test_install_py_stays_below_the_alert(self):
-        cap = shell_cap()
-        size = (REPO_ROOT / "install.py").stat().st_size
-        alert = int(cap * ALERT_SHARE)
-        self.assertLess(
-            size, alert,
-            f"install.py is {size} bytes, past {alert} of the {cap} the one-liners "
-            "accept: raise MAX_INSTALLER_BYTES in install.sh and $maximumInstallerBytes "
-            "in install.ps1, or make the installer smaller")
-
-
-if __name__ == "__main__":
-    unittest.main()