Make network support optional

.circleci/config.yml

@@ -18,9 +18,11 @@ jobs:
       # Build
       - run: cargo build
       - run: cargo build --features logging
+      - run: cargo build --no-default-features
 
       # Run tests
       - run: cargo test
+      - run: cargo test --no-default-features
 
       - save_cache:
           key: v1-cargo-cache-{{ arch }}-{{ .Branch }}

Cargo.toml

@@ -28,17 +28,19 @@ time = "0.1.38"
 toml = "0.4.6"
 walkdir = "2.0.1"
 xdg = "2.1.0"
-reqwest = "0.9.5"
+reqwest = { version = "0.9.5", optional = true }
 
 [dev-dependencies]
 assert_cmd = "0.10"
-escargot = "0.3"
+escargot = "0.4"
 predicates = "1.0"
 tempdir = "^0.3"
 utime = "0.2.0"
 
 [features]
+default = ["networking"]
 logging = ["env_logger"]
+networking = ["reqwest"]
 
 [profile.release]
 lto = true

README.md

@@ -132,6 +132,7 @@ To enable the log output, set the `RUST_LOG` env variable:
     $ export RUST_LOG=tldr=debug
 
 
+
 ## Configuration
 
 The tldr command can be customized with a config file called `config.toml`.
@@ -189,12 +190,25 @@ To run tests:
 
     $ cargo test
 
+(Note that integration tests are a bit slow, since they invoke `cargo build` in different configurations.)
+
 To run lints:
 
     $ rustup component add clippy
     $ cargo clean && cargo clippy
 
 
+## Build Flags
+
+tealdeer knows the following feature flags:
+
+- `logging`: This enables logging support through [env_logger](https://docs.rs/env_logger/*/env_logger/)
+- `networking`: This enables support for updating the cache from the internet
+
+By default, only the `networking` feature is enabled. To build tealdeer without
+networking support, use the `--no-default-features` Cargo flag.
+
+
 ## License
 
 Licensed under either of

src/cache.rs

@@ -1,15 +1,19 @@
+#[cfg(feature = "networking")]
+use std::borrow::Cow;
 use std::env;
 use std::fs;
 use std::io::Read;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
-#[cfg(unix)]
+#[cfg(all(unix, feature = "networking"))]
 use std::os::unix::fs::MetadataExt;
 
+#[cfg(feature = "networking")]
 use reqwest::{Client, Proxy};
 use flate2::read::GzDecoder;
 use log::debug;
 use tar::Archive;
+#[cfg(feature = "networking")]
 use time;
 use walkdir::{DirEntry, WalkDir};
 use xdg::BaseDirectories;
@@ -17,19 +21,36 @@ use xdg::BaseDirectories;
 use crate::error::TealdeerError::{self, CacheError, UpdateError};
 use crate::types::OsType;
 
+/// A cache update source.
+#[derive(Debug)]
+pub enum Source {
+    /// Load the archive from the file system.
+    File(PathBuf),
+
+    /// Load the archive from the network.
+    #[cfg(feature = "networking")]
+    Url(Cow<'static, str>),
+
+    /// No source is defined.
+    #[cfg(not(feature = "networking"))]
+    None,
+}
+
 #[derive(Debug)]
 pub struct Cache {
-    url: String,
+    /// The cache source. Either an URL or a file path.
+    source: Source,
+    /// The target OS type.
     os: OsType,
 }
 
 impl Cache {
-    pub fn new<S>(url: S, os: OsType) -> Self
+    pub fn new<S>(source: S, os: OsType) -> Self
     where
-        S: Into<String>,
+        S: Into<Source>,
     {
         Self {
-            url: url.into(),
+            source: source.into(),
             os,
         }
     }
@@ -60,8 +81,20 @@ impl Cache {
         Ok(xdg_dirs.get_cache_home())
     }
 
-    /// Download the archive
-    fn download(&self) -> Result<Vec<u8>, TealdeerError> {
+    /// Load the archive from the file system.
+    fn load_from_file(path: &Path) -> Result<Vec<u8>, TealdeerError> {
+        let mut f = fs::File::open(path)
+            .map_err(|e| UpdateError(format!("Could not open file: {}", e)))?;
+        let mut buf: Vec<u8> = vec![];
+        let bytes_read = f.read_to_end(&mut buf)
+            .map_err(|e| UpdateError(format!("Could not read file: {}", e)))?;
+        debug!("{} bytes loaded from filesystem", bytes_read);
+        Ok(buf)
+    }
+
+    /// Load the archive from the network.
+    #[cfg(feature = "networking")]
+    fn load_from_network(url: &str) -> Result<Vec<u8>, TealdeerError> {
         let mut builder = Client::builder();
         if let Ok(ref host) = env::var("HTTP_PROXY") {
             if let Ok(proxy) = Proxy::http(host) {
@@ -74,13 +107,31 @@ impl Cache {
             }
         }
         let client = builder.build().unwrap_or_else(|_| Client::new());
-        let mut resp = client.get(&self.url).send()?;
+        let mut resp = client.get(url).send()?;
         let mut buf: Vec<u8> = vec![];
         let bytes_downloaded = resp.copy_to(&mut buf)?;
         debug!("{} bytes downloaded", bytes_downloaded);
         Ok(buf)
     }
 
+    /// Download the archive from the network or load it from a file.
+    #[cfg(feature = "networking")]
+    fn load(&self) -> Result<Vec<u8>, TealdeerError> {
+        match self.source {
+            Source::File(ref path) => Self::load_from_file(path),
+            Source::Url(ref url) => Self::load_from_network(url),
+        }
+    }
+
+    /// Load the archive from the file system.
+    #[cfg(not(feature = "networking"))]
+    fn load(&self) -> Result<Vec<u8>, TealdeerError> {
+        match self.source {
+            Source::File(ref path) => Self::load_from_file(path),
+            Source::None => Err(TealdeerError::UpdateError("No update source defined".into())),
+        }
+    }
+
     /// Decompress and open the archive
     fn decompress<R: Read>(&self, reader: R) -> Archive<GzDecoder<R>> {
         Archive::new(GzDecoder::new(reader))
@@ -88,8 +139,8 @@ impl Cache {
 
     /// Update the pages cache.
     pub fn update(&self) -> Result<(), TealdeerError> {
-        // First, download the compressed data
-        let bytes: Vec<u8> = self.download()?;
+        // First, load the compressed data
+        let bytes: Vec<u8> = self.load()?;
 
         // Decompress the response body into an `Archive`
         let mut archive = self.decompress(&bytes[..]);
@@ -118,7 +169,7 @@ impl Cache {
         Ok(())
     }
 
-    #[cfg(unix)]
+    #[cfg(all(unix, feature = "networking"))]
     /// Return the number of seconds since the cache directory was last modified.
     pub fn last_update(&self) -> Option<i64> {
         if let Ok(cache_dir) = self.get_cache_dir() {

src/error.rs

@@ -1,4 +1,6 @@
 use std::fmt;
+
+#[cfg(feature = "networking")]
 use reqwest::Error as ReqwestError;
 
 #[derive(Debug)]
@@ -9,6 +11,7 @@ pub enum TealdeerError {
     UpdateError(String),
 }
 
+#[cfg(feature = "networking")]
 impl From<ReqwestError> for TealdeerError {
     fn from(err: ReqwestError) -> Self {
         TealdeerError::UpdateError(format!("HTTP error: {}", err.to_string()))

src/main.rs

@@ -16,11 +16,14 @@
 #[cfg(feature = "logging")]
 extern crate env_logger;
 
+#[cfg(feature = "networking")]
+use std::borrow::Cow;
 use std::fs::File;
 use std::io::BufReader;
 use std::path::{Path, PathBuf};
 use std::process;
 
+#[cfg(feature = "networking")]
 use ansi_term::Color;
 use docopt::Docopt;
 use serde_derive::Deserialize;
@@ -32,7 +35,7 @@ mod formatter;
 mod tokenizer;
 mod types;
 
-use crate::cache::Cache;
+use crate::cache::{Cache, Source};
 use crate::config::{get_config_path, make_default_config, Config};
 use crate::error::TealdeerError::{CacheError, ConfigError, UpdateError};
 use crate::formatter::print_lines;
@@ -42,6 +45,8 @@ use crate::types::OsType;
 const NAME: &str = "tealdeer";
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 const USAGE: &str = "
+tealdeer, a fast tldr implementation written in Rust.
+
 Usage:
 
     tldr [options] <command>
@@ -49,16 +54,17 @@ Usage:
 
 Options:
 
-    -h --help           Show this screen
-    -v --version        Show version information
-    -l --list           List all commands in the cache
-    -f --render <file>  Render a specific markdown file
-    -o --os <type>      Override the operating system [linux, osx, sunos]
-    -u --update         Update the local cache
-    -c --clear-cache    Clear the local cache
-    -q --quiet          Suppress informational messages
-    --config-path       Show config file path
-    --seed-config       Create a basic config
+    -h --help               Show this screen
+    -v --version            Show version information
+    -l --list               List all commands in the cache
+    -f --render <file>      Render a specific markdown file
+    -o --os <type>          Override the operating system [linux, osx, sunos]
+    -u --update             Update the local cache from the network
+    -U --update-from <src>  Update the local cache from the specified URL or path
+    -c --clear-cache        Clear the local cache
+    -q --quiet              Suppress informational messages
+    --config-path           Show config file path
+    --seed-config           Create a basic config
 
 Examples:
 
@@ -70,11 +76,19 @@ To control the cache:
     $ tldr --update
     $ tldr --clear-cache
 
+You can also manually specify the archive to be used for updating the cache:
+
+    $ tldr --update-from https://github.com/tldr-pages/tldr/archive/master.tar.gz
+    $ tldr --update-from master.tar.gz
+
 To render a local file (for testing):
 
     $ tldr --render /path/to/file.md
 ";
+
+#[cfg(feature = "networking")]
 const ARCHIVE_URL: &str = "https://github.com/tldr-pages/tldr/archive/master.tar.gz";
+#[cfg(feature = "networking")]
 const MAX_CACHE_AGE: i64 = 2_592_000; // 30 days
 
 #[derive(Debug, Deserialize)]
@@ -86,6 +100,7 @@ struct Args {
     flag_render: Option<String>,
     flag_os: Option<OsType>,
     flag_update: bool,
+    flag_update_from: Option<String>,
     flag_clear_cache: bool,
     flag_quiet: bool,
     flag_config_path: bool,
@@ -119,6 +134,7 @@ fn print_page(path: &Path) -> Result<(), String> {
 }
 
 /// Check the cache for freshness
+#[cfg(feature = "networking")]
 fn check_cache(args: &Args, cache: &Cache) {
     if !args.flag_update {
         match cache.last_update() {
@@ -144,6 +160,14 @@ fn check_cache(args: &Args, cache: &Cache) {
     };
 }
 
+/// Check the cache for freshness
+///
+/// No-op when networking support is disabled.
+#[cfg(not(feature = "networking"))]
+fn check_cache(_args: &Args, _cache: &Cache) {
+    // No-op when no networking support is enabled.
+}
+
 #[cfg(feature = "logging")]
 fn init_log() {
     env_logger::init();
@@ -176,6 +200,28 @@ fn get_os() -> OsType {
     OsType::Other
 }
 
+#[cfg(feature = "networking")]
+fn get_url_source(source: &str) -> Source {
+    Source::Url(Cow::Owned(source.to_string()))
+}
+
+#[cfg(not(feature = "networking"))]
+fn get_url_source(_source: &str) -> Source {
+    eprintln!("tealdeer has been compiled without networking support,");
+    eprintln!("cannot update the cache from a network URL.");
+    process::exit(1);
+}
+
+#[cfg(feature = "networking")]
+fn get_default_source() -> Source {
+    Source::Url(Cow::Borrowed(ARCHIVE_URL))
+}
+
+#[cfg(not(feature = "networking"))]
+fn get_default_source() -> Source {
+    Source::None
+}
+
 fn main() {
     // Initialize logger
     init_log();
@@ -198,8 +244,15 @@ fn main() {
         None => get_os(),
     };
 
+    // Validate cache source
+    let cache_source: Source = match args.flag_update_from {
+        Some(ref src) if src.starts_with("http") => get_url_source(src),
+        Some(ref src) => Source::File(PathBuf::from(src)),
+        None => get_default_source(),
+    };
+
     // Initialize cache
-    let cache = Cache::new(ARCHIVE_URL, os);
+    let cache = Cache::new(cache_source, os);
 
     // Clear cache, pass through
     if args.flag_clear_cache {
@@ -217,7 +270,7 @@ fn main() {
     }
 
     // Update cache, pass through
-    if args.flag_update {
+    if args.flag_update || args.flag_update_from.is_some() {
         cache.update().unwrap_or_else(|e| {
             match e {
                 CacheError(msg) | ConfigError(msg) | UpdateError(msg) => {

tests/lib.rs

@@ -1,11 +1,5 @@
 //! Integration tests.
 
-extern crate assert_cmd;
-extern crate escargot;
-extern crate predicates;
-extern crate tempdir;
-extern crate utime;
-
 use std::fs::File;
 use std::io::Write;
 use std::process::Command;
@@ -20,7 +14,6 @@ struct TestEnv {
     pub config_dir: TempDir,
     pub input_dir: TempDir,
     pub default_features: bool,
-    pub features: Vec<String>,
 }
 
 impl TestEnv {
@@ -30,7 +23,6 @@ impl TestEnv {
             config_dir: TempDir::new(".tldr.test.config").unwrap(),
             input_dir: TempDir::new(".tldr.test.input").unwrap(),
             default_features: true,
-            features: vec![],
         }
     }
 
@@ -40,12 +32,6 @@ impl TestEnv {
         self
     }
 
-    /// Add the specified feature.
-    fn with_feature<S: Into<String>>(mut self, feature: S) -> Self {
-        self.features.push(feature.into());
-        self
-    }
-
     /// Return a new `Command` with env vars set.
     fn command(&self) -> Command {
         let mut build = escargot::CargoBuild::new()
@@ -53,10 +39,9 @@ impl TestEnv {
             .current_release()
             .current_target();
         if !self.default_features {
-            build = build.arg("--no-default-features");
-        }
-        if !self.features.is_empty() {
-            build = build.arg(&format!("--feature {}", self.features.join(",")));
+            build = build
+                .arg("--no-default-features")
+                .target_dir("target/no-default-features");
         }
         let run = build.run().unwrap();
         let mut cmd = run.command();
@@ -257,3 +242,57 @@ fn test_correct_rendering_with_config() {
         .success()
         .stdout(similar(expected));
 }
+
+/// Updating from a network URL should not be possible when networking support
+/// is not enabled.
+#[test]
+fn test_update_from_no_networking() {
+    let testenv = TestEnv::new();
+    testenv
+        .no_default_features()  // Disable networking
+        .command()
+        .args(&["--update-from", "https://github.com/tldr-pages/tldr/archive/master.tar.gz"])
+        .assert()
+        .failure()
+        .stderr(contains("compiled without networking support"))
+        .stderr(contains("cannot update the cache from a network URL"));
+}
+
+/// Updating from an invalid URL should result in an error message.
+#[test]
+fn test_update_from_invalid_url() {
+    let testenv = TestEnv::new();
+    testenv
+        .command()
+        .args(&["--update-from", "httpsss:github.com/tldr-pages/tldr/archive/master.tar.gz"])
+        .assert()
+        .failure()
+        .stderr(contains("Could not update cache: HTTP error"))
+        .stderr(contains("URL scheme is not allowed"));
+}
+
+/// Updating from the wrong (non-gzip-archive) URL should result in an error.
+#[test]
+fn test_update_from_wrong_url() {
+    let testenv = TestEnv::new();
+    testenv
+        .command()
+        .args(&["--update-from", "https://tldr.sh/"])
+        .assert()
+        .failure()
+        .stderr(contains("Could not update cache: Could not unpack compressed data"));
+}
+
+/// When a path is specified that does not exist, an error message should be shown.
+#[test]
+fn test_update_from_missing_path() {
+    let testenv = TestEnv::new();
+    testenv
+        .no_default_features()
+        .command()
+        .args(&["--update-from", "ajsdfasjdkfljasdf"])  // Invalid path
+        .assert()
+        .failure()
+        .stderr(contains("Could not update cache: Could not open file:"))
+        .stderr(contains("No such file or directory"));
+}