Cleanup, generate nb links from pre-commit

scripts/make-exercises.sh

+#!/bin/bash
+
+set -e
+
+cd "$(git rev-parse --show-toplevel)"
+
+git rm -qf exercises/*.ipynb
+for nb in exercises/solutions/*.ipynb; do
+    target="exercises/$(basename "$nb")"
+    filter=$(git check-attr filter "$target" | sed 's/.* //')
+    if [[ -n "$filter" ]]; then
+        cat "$nb" | $(git config filter."$filter".clean) > "$target"
+    else
+        cp "$nb" "$target"
+    fi
+done

scripts/make-nb-links.py

+#!/usr/bin/python3
+
+from plumbum import local
+from plumbum.cmd import git
+
+local.cwd.chdir(git('rev-parse', '--show-toplevel').strip())
+
+readme = local.cwd / 'README.md'
+tmp = local.cwd / 'README.md.tmp'
+
+# jump to correct place and save stuff up to start of list
+with readme.open('r') as f, tmp.open('w') as fout:
+    flag = True
+    for line in f:
+        if flag:
+            fout.write(line)
+
+        if not flag and line.find("## ") != -1:
+            flag = True
+            fout.write(line)
+
+        if flag and line.find("## lecture notes") != -1:
+            flag = False
+            fout.write("\n")
+            for nb in sorted(local.path("lecture/") // "*.ipynb"):
+                title = nb.basename.replace(".ipynb", "")
+                link = "* [{}](http://nbviewer.jupyter.org/urls/gitlab.gwdg.de/jschulz1/haskell_labcourse/raw/master/lecture/{}.ipynb)\n".format(title, title)
+                print(link)
+                fout.write(link)
+            fout.write("\n")
+
+tmp.rename(readme)

scripts/makenblinks.py

-#!/usr/bin/python3
-
-from plumbum import local
-from os import rename
-
-header = "## lecture notes\nviewed in nbviewer directly from the repository\n\n"
-
-f = open('README.md', 'r')
-fout = open('README_tmp.md', 'w')
-
-# jump to correct place and  save stuff up to start of list
-flag = True
-for line in f:
-    if flag:
-        fout.write(line)
-
-    if not flag and line.find("## ") != -1:
-        flag = True
-        fout.write(line)
-
-    if flag and line.find("## lecture notes") != -1:
-        flag = False
-        fout.write("\n")
-        for nb in sorted(local.path("lecture/") // "*.ipynb"):
-            title = nb.basename.replace(".ipynb", "")
-            link = "* [{}](http://nbviewer.jupyter.org/urls/gitlab.gwdg.de/jschulz1/haskell_labcourse/raw/master/lecture/{}.ipynb)\n".format(title, title)
-            print(link)
-            fout.write(link)
-        fout.write("\n")
-
-f.close()
-fout.close()
-
-rename("README_tmp.md", "README.md")

scripts/pre-commit.sh

 #!/bin/bash
 
-set -e
 exec 2>&1
 
 cd "$(git rev-parse --show-toplevel)"
 
+stashed=false
+
+stash() {
+    if ! $stashed; then
+       git stash -q --keep-index
+       stashed=true
+    fi
+}
+
+stash-pop() {
+    $stashed && git stash pop -q
+}
+
+trap stash-pop EXIT
+
 if git diff --cached --name-only | grep -q '^exercises/'; then
-    git stash -q --keep-index
-    git rm -f exercises/*.ipynb
-    for nb in exercises/solutions/*.ipynb; do
-        target="exercises/$(basename "$nb")"
-        cat "$nb" | $(git config filter.ipynb-codecells.clean) > "$target"
-        git add "$target"
-    done
-    git stash pop -q
+    stash
+    scripts/make-exercises.sh || exit 1
+    git add exercises/*.ipynb
+fi
+
+if git diff --cached --name-only | grep -q '^lecture/'; then
+    stash
+    # TODO: Ignore errors here for now, in case plumbum is not available.
+    scripts/make-nb-links.py
+    git add README.md
 fi
 
 exit 0