Add file-backed appearance config for font overrides

apps/server/src/appearance.test.ts

@@ -0,0 +1,164 @@
+import { AppearanceConfig, type AppearanceConfigIssue } from "@t3tools/contracts";
+import * as NodeServices from "@effect/platform-node/NodeServices";
+import { assert, it } from "@effect/vitest";
+import { Effect, Fiber, FileSystem, Layer, Path, Schema, Stream } from "effect";
+import { ServerConfig, type ServerConfigShape } from "./config";
+
+import { Appearance, AppearanceLive, DEFAULT_APPEARANCE_CONFIG } from "./appearance";
+
+const AppearanceConfigJson = Schema.fromJsonString(AppearanceConfig);
+
+const makeAppearanceLayer = (
+  resolveAppearanceConfigPath?: (stateDir: string, join: Path.Path["join"]) => string,
+) =>
+  AppearanceLive.pipe(
+    Layer.provideMerge(
+      Layer.effect(
+        ServerConfig,
+        Effect.gen(function* () {
+          const fs = yield* FileSystem.FileSystem;
+          const { join } = yield* Path.Path;
+          const dir = yield* fs.makeTempDirectoryScoped({ prefix: "t3code-appearance-test-" });
+          const appearanceConfigPath =
+            resolveAppearanceConfigPath?.(dir, join) ?? join(dir, "appearance.json");
+          return { appearanceConfigPath } as ServerConfigShape;
+        }),
+      ),
+    ),
+  );
+
+const readAppearanceConfig = (configPath: string) =>
+  Effect.gen(function* () {
+    const fileSystem = yield* FileSystem.FileSystem;
+    const rawConfig = yield* fileSystem.readFileString(configPath);
+    return yield* Schema.decodeUnknownEffect(AppearanceConfigJson)(rawConfig);
+  });
+
+it.layer(NodeServices.layer)("appearance", (it) => {
+  it.effect("bootstraps default appearance when config file is missing", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const { appearanceConfigPath } = yield* ServerConfig;
+      assert.isFalse(yield* fs.exists(appearanceConfigPath));
+
+      yield* Effect.gen(function* () {
+        const appearance = yield* Appearance;
+        yield* appearance.syncDefaultAppearanceOnStartup;
+      });
+
+      const persisted = yield* readAppearanceConfig(appearanceConfigPath);
+      assert.deepEqual(persisted, DEFAULT_APPEARANCE_CONFIG);
+    }).pipe(Effect.provide(makeAppearanceLayer())),
+  );
+
+  it.effect("bootstraps default appearance when parent directory is missing", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const { appearanceConfigPath } = yield* ServerConfig;
+      assert.isFalse(yield* fs.exists(appearanceConfigPath));
+
+      yield* Effect.gen(function* () {
+        const appearance = yield* Appearance;
+        yield* appearance.syncDefaultAppearanceOnStartup;
+      });
+
+      const persisted = yield* readAppearanceConfig(appearanceConfigPath);
+      assert.deepEqual(persisted, DEFAULT_APPEARANCE_CONFIG);
+    }).pipe(
+      Effect.provide(
+        makeAppearanceLayer((dir, join) => join(dir, "nested", "state", "appearance.json")),
+      ),
+    ),
+  );
+
+  it.effect("uses defaults in runtime when config is malformed without overriding file", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const { appearanceConfigPath } = yield* ServerConfig;
+      yield* fs.writeFileString(appearanceConfigPath, "{ not-json");
+
+      const configState = yield* Effect.gen(function* () {
+        const appearance = yield* Appearance;
+        return yield* appearance.loadConfigState;
+      });
+
+      assert.deepEqual(configState.appearance, DEFAULT_APPEARANCE_CONFIG);
+      assert.deepEqual(configState.issues, [
+        {
+          kind: "appearance.malformed-config",
+          message: configState.issues[0]?.message ?? "",
+        },
+      ]);
+      assert.equal(yield* fs.readFileString(appearanceConfigPath), "{ not-json");
+    }).pipe(Effect.provide(makeAppearanceLayer())),
+  );
+
+  it.effect("keeps valid appearance fields and reports invalid ones", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const { appearanceConfigPath } = yield* ServerConfig;
+      yield* fs.writeFileString(
+        appearanceConfigPath,
+        JSON.stringify({
+          uiFontFamily: '"IBM Plex Sans", system-ui, sans-serif',
+          uiFontSizePx: 30,
+          monoFontFamily: '"Iosevka", monospace',
+          terminalFontSizePx: "big",
+        }),
+      );
+
+      const configState = yield* Effect.gen(function* () {
+        const appearance = yield* Appearance;
+        return yield* appearance.loadConfigState;
+      });
+
+      assert.deepEqual(configState.appearance, {
+        uiFontFamily: '"IBM Plex Sans", system-ui, sans-serif',
+        uiFontSizePx: DEFAULT_APPEARANCE_CONFIG.uiFontSizePx,
+        monoFontFamily: '"Iosevka", monospace',
+        terminalFontSizePx: DEFAULT_APPEARANCE_CONFIG.terminalFontSizePx,
+      });
+      assert.deepEqual(configState.issues, [
+        {
+          kind: "appearance.invalid-value",
+          field: "uiFontSizePx",
+          message: configState.issues[0]?.message ?? "",
+        },
+        {
+          kind: "appearance.invalid-value",
+          field: "terminalFontSizePx",
+          message: configState.issues[1]?.message ?? "",
+        },
+      ] satisfies AppearanceConfigIssue[]);
+    }).pipe(Effect.provide(makeAppearanceLayer())),
+  );
+
+  it.effect("emits change events when appearance config changes on disk", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const { appearanceConfigPath } = yield* ServerConfig;
+      const appearance = yield* Appearance;
+
+      yield* appearance.syncDefaultAppearanceOnStartup;
+
+      const changeFiber = yield* Stream.runHead(appearance.changes).pipe(Effect.forkChild);
+      yield* fs.writeFileString(appearanceConfigPath, "{ not-json");
+      const change = yield* Fiber.join(changeFiber);
+
+      assert.equal(change._tag, "Some");
+      if (change._tag !== "Some") {
+        return;
+      }
+
+      assert.deepEqual(change.value, {
+        changedSections: ["appearance"],
+        issues: [
+          {
+            kind: "appearance.malformed-config",
+            message: change.value.issues[0]?.message ?? "",
+          },
+        ],
+      });
+    }).pipe(Effect.provide(makeAppearanceLayer())),
+  );
+});