From 0e33145aa6aa8307fd44b554b5c4624572dc718f Mon Sep 17 00:00:00 2001
From: "J. Kirby Ross" <james@flyingrobots.dev>
Date: Mon, 27 Oct 2025 07:42:11 -0700
Subject: [PATCH 1/2] chore: add .editorconfig and pre-commit rustfmt check
 (opt-in via make hooks)

---
 .editorconfig        | 16 ++++++++++++++++
 .githooks/pre-commit | 15 +++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 .editorconfig

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..f31040a
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,16 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+[*.{md,mdx}]
+trim_trailing_whitespace = false
+
+[*.{ts,tsx,js,json}]
+indent_size = 2
+
diff --git a/.githooks/pre-commit b/.githooks/pre-commit
index 2c97a1f..51a8c23 100644
--- a/.githooks/pre-commit
+++ b/.githooks/pre-commit
@@ -51,3 +51,18 @@ fi
 
 exit 0
 
+# Format gate: run rustfmt check if Rust files are staged
+if git diff --cached --name-only | grep -E '\.rs$' >/dev/null; then
+  echo "[pre-commit] Running cargo fmt --all -- --check ..."
+  if ! cargo fmt --all -- --check; then
+    cat <<'EOM' >&2
+[pre-commit] Formatting check failed.
+
+Run:  cargo fmt --all
+
+Our policy is to keep the tree rustfmt-clean to reduce review noise and
+merge conflicts. The CI also enforces this gate.
+EOM
+    exit 1
+  fi
+fi

From 225778a7d68344e561f76b1f545778c2177fd5aa Mon Sep 17 00:00:00 2001
From: "J. Kirby Ross" <james@flyingrobots.dev>
Date: Wed, 29 Oct 2025 09:06:21 -0700
Subject: [PATCH 2/2] docs(hooks-formatting): update execution plan + decision
 log; fix pre-commit to run rustfmt without early exit

---
 .githooks/pre-commit   | 74 +++++++++++++++++++-----------------------
 docs/decision-log.md   |  7 ++++
 docs/execution-plan.md |  6 ++++
 3 files changed, 46 insertions(+), 41 deletions(-)

diff --git a/.githooks/pre-commit b/.githooks/pre-commit
index 51a8c23..f9b9fa1 100644
--- a/.githooks/pre-commit
+++ b/.githooks/pre-commit
@@ -2,55 +2,47 @@
 set -euo pipefail
 
 # Enforce coupling between PRNG algorithm/version and golden regression vector.
-
 PRNG_FILE="crates/rmg-core/src/math/prng.rs"
+if git diff --cached --name-only | grep -qx "$PRNG_FILE"; then
+  DIFF=$(git diff --cached -- "$PRNG_FILE" || true)
+  # Heuristics to detect algorithm changes: edits to these functions imply behavior change
+  if echo "$DIFF" | grep -E '^(\+|-)\s*(fn\s+next_u64|fn\s+from_seed_u64|fn\s+from_seed\(|fn\s+next_int\()' >/dev/null; then
+    ALGO_CHANGED=1
+  else
+    ALGO_CHANGED=0
+  fi
 
-# Only run if the PRNG file is staged
-if ! git diff --cached --name-only | grep -qx "$PRNG_FILE"; then
-  exit 0
-fi
-
-DIFF=$(git diff --cached -- "$PRNG_FILE" || true)
-
-# Heuristics to detect algorithm changes: edits to these functions imply behavior change
-if echo "$DIFF" | grep -E '^(\+|-)\s*(fn\s+next_u64|fn\s+from_seed_u64|fn\s+from_seed\(|fn\s+next_int\()' >/dev/null; then
-  ALGO_CHANGED=1
-else
-  ALGO_CHANGED=0
-fi
-
-# Version bump present?
-if echo "$DIFF" | grep -E 'PRNG_ALGO_VERSION' >/dev/null; then
-  VERSION_CHANGED=1
-else
-  VERSION_CHANGED=0
-fi
+  # Version bump present?
+  if echo "$DIFF" | grep -E 'PRNG_ALGO_VERSION' >/dev/null; then
+    VERSION_CHANGED=1
+  else
+    VERSION_CHANGED=0
+  fi
 
-# Golden regression vector updated?
-if echo "$DIFF" | grep -E 'next_int_golden_regression|assert_eq!\(values,\s*vec!\[' >/dev/null; then
-  GOLDEN_CHANGED=1
-else
-  GOLDEN_CHANGED=0
-fi
+  # Golden regression vector updated?
+  if echo "$DIFF" | grep -E 'next_int_golden_regression|assert_eq!\(values,\s*vec!\[' >/dev/null; then
+    GOLDEN_CHANGED=1
+  else
+    GOLDEN_CHANGED=0
+  fi
 
-FAIL=0
-if [[ "$ALGO_CHANGED" -eq 1 && "$VERSION_CHANGED" -eq 0 ]]; then
-  echo "pre-commit: PRNG algorithm changed but PRNG_ALGO_VERSION was not bumped." >&2
-  FAIL=1
-fi
+  FAIL=0
+  if [[ "$ALGO_CHANGED" -eq 1 && "$VERSION_CHANGED" -eq 0 ]]; then
+    echo "pre-commit: PRNG algorithm changed but PRNG_ALGO_VERSION was not bumped." >&2
+    FAIL=1
+  fi
 
-if [[ "$VERSION_CHANGED" -eq 1 && "$GOLDEN_CHANGED" -eq 0 ]]; then
-  echo "pre-commit: PRNG_ALGO_VERSION bumped but golden regression vector was not updated." >&2
-  FAIL=1
-fi
+  if [[ "$VERSION_CHANGED" -eq 1 && "$GOLDEN_CHANGED" -eq 0 ]]; then
+    echo "pre-commit: PRNG_ALGO_VERSION bumped but golden regression vector was not updated." >&2
+    FAIL=1
+  fi
 
-if [[ "$FAIL" -eq 1 ]]; then
-  echo "pre-commit: Refusing commit. Update algorithm version and golden regression together." >&2
-  exit 1
+  if [[ "$FAIL" -eq 1 ]]; then
+    echo "pre-commit: Refusing commit. Update algorithm version and golden regression together." >&2
+    exit 1
+  fi
 fi
 
-exit 0
-
 # Format gate: run rustfmt check if Rust files are staged
 if git diff --cached --name-only | grep -E '\.rs$' >/dev/null; then
   echo "[pre-commit] Running cargo fmt --all -- --check ..."
diff --git a/docs/decision-log.md b/docs/decision-log.md
index b74a1b6..7acd5cc 100644
--- a/docs/decision-log.md
+++ b/docs/decision-log.md
@@ -14,3 +14,10 @@
 | 2025-10-26 | EPI bundle | Adopt entropy, plugin, inspector, runtime config specs (Phase 0.75) | Close causality & extensibility gap | Phase 1 implementation backlog defined |
 | 2025-10-26 | RMG + Confluence | Adopt RMG v2 (typed DPOi engine) and Confluence synchronization as core architecture | Unify runtime/persistence/tooling on deterministic rewrites | Launch Rust workspace (rmg-core/ffi/wasm/cli), port ECS rules, set up Confluence networking |
 | 2025-10-27 | Core math split | Split `rmg-core` math into focused submodules (`vec3`, `mat4`, `quat`, `prng`) replacing monolithic `math.rs`. | Improves readability, testability, and aligns with strict linting. | Update imports; no behavior changes intended; follow-up determinism docs in snapshot hashing. |
+
+## 2025-10-29 — Hooks formatting gate (PR #12)
+
+- Context: Enforce consistent formatting before commit; avoid CI/docs drift when non-doc files change.
+- Decision: Pre-commit runs `cargo fmt --all -- --check` whenever staged Rust files are detected. Retain the PRNG coupling guard but remove the unconditional early exit so formatting still runs when the PRNG file isn’t staged.
+- EditorConfig: normalize line endings (LF), ensure final newline, trim trailing whitespace, set 2-space indent for JS/TS/JSON and 4-space for Rust.
+- Consequence: Developers get immediate feedback on formatting; cleaner diffs and fewer CI round-trips.
diff --git a/docs/execution-plan.md b/docs/execution-plan.md
index cfe0d6e..a9f3ef2 100644
--- a/docs/execution-plan.md
+++ b/docs/execution-plan.md
@@ -33,6 +33,12 @@ This is Codex’s working map for building Echo. Update it relentlessly—each s
 
 ## Today’s Intent
 
+> 2025-10-29 — Hooks formatting gate (PR #12)
+
+- Pre-commit: add rustfmt check for staged Rust files (`cargo fmt --all -- --check`).
+- Keep PRNG coupling guard, but avoid early exit so formatting still runs when PRNG file isn't staged.
+- .editorconfig: unify whitespace rules (LF, trailing newline, 2-space for JS/TS, 4-space for Rust).
+
 > 2025-10-27 — Core math modularization (PR #5)
 
 - **Focus**: Split `rmg-core` math into focused submodules (`vec3`, `mat4`, `quat`, `prng`).