Rust learning: lessons, notes, and exercise crates

2026-09-06 23:59:08 +07:00
commit 6ddf41aa81
119 changed files with 10873 additions and 0 deletions
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+#!/usr/bin/env bash
+# 0009 — the mutation check.
+#
+# Copies your crate to a temp dir, plants ONE deliberate bug in the copy, and
+# runs YOUR tests against it. Your own files are never touched.
+#
+#   killed   = your tests noticed the bug. Good.
+#   SURVIVED = the bug is invisible to your suite. Write the missing test.
+#   SKIP     = the pattern is not in your source, so nothing was planted.
+#
+# Usage:  bash 0009-mutants.sh ~/learn-rust/tasks
+
+set -u
+crate=$(cd "${1:-.}" && pwd)
+work=$(mktemp -d)
+export CARGO_TARGET_DIR=$work/target
+killed=0 survived=0 skipped=0
+
+# name <TAB> file <TAB> sed expression
+mutants=$(cat <<'EOF'
+stats-order	src/cli.rs	s/Priority::High, Priority::Medium, Priority::Low/Priority::Low, Priority::Medium, Priority::High/
+stats-zero	src/cli.rs	s/unwrap_or(0)/unwrap_or(1)/
+clear-count	src/cli.rs	s/remove_completed()/remove_completed() + 1/
+list-format	src/task.rs	s/({})"/{}"/
+status-parse	src/task.rs	s/"in-progress" =>/"inprogress" =>/
+command-case	src/command.rs	s/to_lowercase()/to_string()/
+EOF
+)
+
+echo "crate: $crate"
+while IFS=$'\t' read -r name file expr; do
+    d=$(mktemp -d)
+    cp -r "$crate/src" "$crate/tests" "$crate/Cargo.toml" "$crate/Cargo.lock" "$d/"
+
+    if [ ! -f "$d/$file" ]; then
+        printf '  SKIP     %-13s %s does not exist yet\n' "$name" "$file"
+        skipped=$((skipped + 1))
+        continue
+    fi
+
+    before=$(md5sum <"$d/$file")
+    sed -i "$expr" "$d/$file"
+    if [ "$before" = "$(md5sum <"$d/$file")" ]; then
+        printf '  SKIP     %-13s pattern not found in %s\n' "$name" "$file"
+        skipped=$((skipped + 1))
+        continue
+    fi
+
+    if ! (cd "$d" && cargo build --tests -q) >/dev/null 2>&1; then
+        printf '  SKIP     %-13s mutant does not compile\n' "$name"
+        skipped=$((skipped + 1))
+        continue
+    fi
+
+    if (cd "$d" && cargo test -q) >/dev/null 2>&1; then
+        printf '  SURVIVED %-13s %s\n' "$name" "$file"
+        survived=$((survived + 1))
+    else
+        printf '  killed   %-13s %s\n' "$name" "$file"
+        killed=$((killed + 1))
+    fi
+done <<<"$mutants"
+
+printf '\n%d killed, %d survived, %d skipped\n' "$killed" "$survived" "$skipped"
+[ "$survived" -eq 0 ]