add outputs python-version and python-cache-hit (#728)

This commit splits up the "normal" cache containing the dependencies and
the "python" cache containing the python binaries. This will lead to a
one-time invalidation of caches.

Closes: #713

src/cache/restore-cache.ts

@@ -1,6 +1,5 @@
 import * as cache from "@actions/cache";
 import * as core from "@actions/core";
-import * as exec from "@actions/exec";
 import { hashFiles } from "../hash/hash-files";
 import {
   cacheDependencyGlob,
@@ -9,52 +8,75 @@ import {
   cacheSuffix,
   pruneCache,
   pythonDir,
-  pythonVersion as pythonVersionInput,
   restoreCache as shouldRestoreCache,
-  workingDirectory,
 } from "../utils/inputs";
 import { getArch, getOSNameVersion, getPlatform } from "../utils/platforms";
 
 export const STATE_CACHE_KEY = "cache-key";
 export const STATE_CACHE_MATCHED_KEY = "cache-matched-key";
+export const STATE_PYTHON_CACHE_MATCHED_KEY = "python-cache-matched-key";
+
 const CACHE_VERSION = "2";
 
-export async function restoreCache(): Promise<void> {
-  const cacheKey = await computeKeys();
+export async function restoreCache(pythonVersion?: string): Promise<void> {
+  const cacheKey = await computeKeys(pythonVersion);
   core.saveState(STATE_CACHE_KEY, cacheKey);
   core.setOutput("cache-key", cacheKey);
 
   if (!shouldRestoreCache) {
     core.info("restore-cache is false. Skipping restore cache step.");
+    core.setOutput("python-cache-hit", false);
     return;
   }
 
-  let matchedKey: string | undefined;
-  core.info(
-    `Trying to restore uv cache from GitHub Actions cache with key: ${cacheKey}`,
-  );
   if (cacheLocalPath === undefined) {
     throw new Error(
       "cache-local-path is not set. Cannot restore cache without a valid cache path.",
     );
   }
-  const cachePaths = [cacheLocalPath.path];
+
+  await restoreCacheFromKey(
+    cacheKey,
+    cacheLocalPath.path,
+    STATE_CACHE_MATCHED_KEY,
+    "cache-hit",
+  );
+
   if (cachePython) {
-    cachePaths.push(pythonDir);
+    await restoreCacheFromKey(
+      `${cacheKey}-python`,
+      pythonDir,
+      STATE_PYTHON_CACHE_MATCHED_KEY,
+      "python-cache-hit",
+    );
+  } else {
+    core.setOutput("python-cache-hit", false);
   }
+}
+
+async function restoreCacheFromKey(
+  cacheKey: string,
+  cachePath: string,
+  stateKey: string,
+  outputKey: string,
+): Promise<void> {
+  core.info(
+    `Trying to restore cache from GitHub Actions cache with key: ${cacheKey}`,
+  );
+  let matchedKey: string | undefined;
   try {
-    matchedKey = await cache.restoreCache(cachePaths, cacheKey);
+    matchedKey = await cache.restoreCache([cachePath], cacheKey);
   } catch (err) {
     const message = (err as Error).message;
     core.warning(message);
-    core.setOutput("cache-hit", false);
+    core.setOutput(outputKey, false);
     return;
   }
 
-  handleMatchResult(matchedKey, cacheKey);
+  handleMatchResult(matchedKey, cacheKey, stateKey, outputKey);
 }
 
-async function computeKeys(): Promise<string> {
+async function computeKeys(pythonVersion?: string): Promise<string> {
   let cacheDependencyPathHash = "-";
   if (cacheDependencyGlob !== "") {
     core.info(
@@ -71,58 +93,27 @@ async function computeKeys(): Promise<string> {
     cacheDependencyPathHash = "-no-dependency-glob";
   }
   const suffix = cacheSuffix ? `-${cacheSuffix}` : "";
-  const pythonVersion = await getPythonVersion();
+  const version = pythonVersion ?? "unknown";
   const platform = await getPlatform();
   const osNameVersion = getOSNameVersion();
   const pruned = pruneCache ? "-pruned" : "";
   const python = cachePython ? "-py" : "";
-  return `setup-uv-${CACHE_VERSION}-${getArch()}-${platform}-${osNameVersion}-${pythonVersion}${pruned}${python}${cacheDependencyPathHash}${suffix}`;
-}
-
-async function getPythonVersion(): Promise<string> {
-  if (pythonVersionInput !== "") {
-    return pythonVersionInput;
-  }
-
-  let output = "";
-  const options: exec.ExecOptions = {
-    listeners: {
-      stdout: (data: Buffer) => {
-        output += data.toString();
-      },
-    },
-    silent: !core.isDebug(),
-  };
-
-  try {
-    const execArgs = ["python", "find", "--directory", workingDirectory];
-    await exec.exec("uv", execArgs, options);
-    const pythonPath = output.trim();
-
-    output = "";
-    await exec.exec(pythonPath, ["--version"], options);
-    // output is like "Python 3.8.10"
-    return output.split(" ")[1].trim();
-  } catch (error) {
-    const err = error as Error;
-    core.debug(`Failed to get python version from uv. Error: ${err.message}`);
-    return "unknown";
-  }
+  return `setup-uv-${CACHE_VERSION}-${getArch()}-${platform}-${osNameVersion}-${version}${pruned}${python}${cacheDependencyPathHash}${suffix}`;
 }
 
 function handleMatchResult(
   matchedKey: string | undefined,
   primaryKey: string,
+  stateKey: string,
+  outputKey: string,
 ): void {
   if (!matchedKey) {
     core.info(`No GitHub Actions cache found for key: ${primaryKey}`);
-    core.setOutput("cache-hit", false);
+    core.setOutput(outputKey, false);
     return;
   }
 
-  core.saveState(STATE_CACHE_MATCHED_KEY, matchedKey);
-  core.info(
-    `uv cache restored from GitHub Actions cache with key: ${matchedKey}`,
-  );
-  core.setOutput("cache-hit", true);
+  core.saveState(stateKey, matchedKey);
+  core.info(`cache restored from GitHub Actions cache with key: ${matchedKey}`);
+  core.setOutput(outputKey, true);
 }

src/save-cache.ts

@@ -6,6 +6,7 @@ import * as pep440 from "@renovatebot/pep440";
 import {
   STATE_CACHE_KEY,
   STATE_CACHE_MATCHED_KEY,
+  STATE_PYTHON_CACHE_MATCHED_KEY,
 } from "./cache/restore-cache";
 import { STATE_UV_PATH, STATE_UV_VERSION } from "./utils/constants";
 import {
@@ -52,63 +53,30 @@ async function saveCache(): Promise<void> {
   }
   if (matchedKey === cacheKey) {
     core.info(`Cache hit occurred on key ${cacheKey}, not saving cache.`);
-    return;
-  }
+  } else {
+    if (shouldPruneCache) {
+      await pruneCache();
+    }
 
-  if (shouldPruneCache) {
-    await pruneCache();
-  }
-
-  if (cacheLocalPath === undefined) {
-    throw new Error(
-      "cache-local-path is not set. Cannot save cache without a valid cache path.",
-    );
-  }
-  let actualCachePath = cacheLocalPath.path;
-  if (
-    process.env.UV_CACHE_DIR &&
-    process.env.UV_CACHE_DIR !== cacheLocalPath.path
-  ) {
-    core.warning(
-      `The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${cacheLocalPath.path}".`,
-    );
-    actualCachePath = process.env.UV_CACHE_DIR;
-  }
-
-  core.info(`Saving cache path: ${actualCachePath}`);
-  if (!fs.existsSync(actualCachePath) && !ignoreNothingToCache) {
-    throw new Error(
+    const actualCachePath = getUvCachePath();
+    await saveCacheToKey(
+      cacheKey,
+      actualCachePath,
+      STATE_CACHE_MATCHED_KEY,
+      "uv cache",
       `Cache path ${actualCachePath} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`,
     );
   }
 
-  const cachePaths = [actualCachePath];
   if (cachePython) {
-    core.info(`Including Python cache path: ${pythonDir}`);
-    if (!fs.existsSync(pythonDir) && !ignoreNothingToCache) {
-      throw new Error(
-        `Python cache path ${pythonDir} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`,
-      );
-    }
-    cachePaths.push(pythonDir);
-  }
-
-  core.info(`Final cache paths: ${cachePaths.join(", ")}`);
-  try {
-    await cache.saveCache(cachePaths, cacheKey);
-    core.info(`cache saved with the key: ${cacheKey}`);
-  } catch (e) {
-    if (
-      e instanceof Error &&
-      e.message ===
-        "Path Validation Error: Path(s) specified in the action for caching do(es) not exist, hence no cache is being saved."
-    ) {
-      core.info(
-        "No cacheable paths were found. Ignoring because ignore-nothing-to-save is enabled.",
-      );
-    } else {
-      throw e;
-    }
+    const pythonCacheKey = `${cacheKey}-python`;
+    await saveCacheToKey(
+      pythonCacheKey,
+      pythonDir,
+      STATE_PYTHON_CACHE_MATCHED_KEY,
+      "Python cache",
+      `Python cache path ${pythonDir} does not exist on disk. This likely indicates that there are no Python installations to cache. Consider disabling the cache input if it is not needed.`,
+    );
   }
 }
 
@@ -128,4 +96,61 @@ async function pruneCache(): Promise<void> {
   await exec.exec(uvPath, execArgs, options);
 }
 
+function getUvCachePath(): string {
+  if (cacheLocalPath === undefined) {
+    throw new Error(
+      "cache-local-path is not set. Cannot save cache without a valid cache path.",
+    );
+  }
+  if (
+    process.env.UV_CACHE_DIR &&
+    process.env.UV_CACHE_DIR !== cacheLocalPath.path
+  ) {
+    core.warning(
+      `The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${cacheLocalPath.path}".`,
+    );
+    return process.env.UV_CACHE_DIR;
+  }
+  return cacheLocalPath.path;
+}
+
+async function saveCacheToKey(
+  cacheKey: string,
+  cachePath: string,
+  stateKey: string,
+  cacheName: string,
+  pathNotExistErrorMessage: string,
+): Promise<void> {
+  const matchedKey = core.getState(stateKey);
+
+  if (matchedKey === cacheKey) {
+    core.info(
+      `${cacheName} hit occurred on key ${cacheKey}, not saving cache.`,
+    );
+    return;
+  }
+
+  core.info(`Including ${cacheName} path: ${cachePath}`);
+  if (!fs.existsSync(cachePath) && !ignoreNothingToCache) {
+    throw new Error(pathNotExistErrorMessage);
+  }
+
+  try {
+    await cache.saveCache([cachePath], cacheKey);
+    core.info(`${cacheName} saved with key: ${cacheKey}`);
+  } catch (e) {
+    if (
+      e instanceof Error &&
+      e.message ===
+        "Path Validation Error: Path(s) specified in the action for caching do(es) not exist, hence no cache is being saved."
+    ) {
+      core.info(
+        `No cacheable ${cacheName} paths were found. Ignoring because ignore-nothing-to-save is enabled.`,
+      );
+    } else {
+      throw e;
+    }
+  }
+}
+
 run();

src/setup-uv.ts

@@ -36,6 +36,37 @@ import {
 } from "./utils/platforms";
 import { getUvVersionFromFile } from "./version/resolve";
 
+async function getPythonVersion(): Promise<string> {
+  if (pythonVersion !== "") {
+    return pythonVersion;
+  }
+
+  let output = "";
+  const options: exec.ExecOptions = {
+    listeners: {
+      stdout: (data: Buffer) => {
+        output += data.toString();
+      },
+    },
+    silent: !core.isDebug(),
+  };
+
+  try {
+    const execArgs = ["python", "find", "--directory", workingDirectory];
+    await exec.exec("uv", execArgs, options);
+    const pythonPath = output.trim();
+
+    output = "";
+    await exec.exec(pythonPath, ["--version"], options);
+    // output is like "Python 3.8.10"
+    return output.split(" ")[1].trim();
+  } catch (error) {
+    const err = error as Error;
+    core.debug(`Failed to get python version from uv. Error: ${err.message}`);
+    return "unknown";
+  }
+}
+
 async function run(): Promise<void> {
   detectEmptyWorkdir();
   const platform = await getPlatform();
@@ -63,8 +94,11 @@ async function run(): Promise<void> {
     core.saveState(STATE_UV_VERSION, setupResult.version);
     core.info(`Successfully installed uv version ${setupResult.version}`);
 
+    const pythonVersion = await getPythonVersion();
+    core.setOutput("python-version", pythonVersion);
+
     if (enableCache) {
-      await restoreCache();
+      await restoreCache(pythonVersion);
     }
     // https://github.com/nodejs/node/issues/56645#issuecomment-3077594952
     await new Promise((resolve) => setTimeout(resolve, 50));