fix(command_test): select correct webdriver version

src/test/webdriver.rs

@@ -1,12 +1,22 @@
 //! Getting WebDriver client binaries.
 
+mod chromedriver;
+mod geckodriver;
+mod safaridriver;
+
 use binary_install::Cache;
 use failure;
-use install::InstallMode;
 use std::path::PathBuf;
-use target;
 use PBAR;
 
+pub use self::{
+    chromedriver::{get_or_install_chromedriver, install_chromedriver},
+    geckodriver::{get_or_install_geckodriver, install_geckodriver},
+    safaridriver::get_safaridriver,
+};
+
+// ------ driver helpers  ------
+
 fn get_and_notify(
     cache: &Cache,
     installation_allowed: bool,
@@ -25,100 +35,11 @@ fn get_and_notify(
     }
 }
 
-/// Get the path to an existing `chromedriver`, or install it if no existing
+struct Collector(Vec<u8>);
-/// binary is found.
-pub fn get_or_install_chromedriver(
-    cache: &Cache,
-    mode: InstallMode,
-) -> Result<PathBuf, failure::Error> {
-    if let Ok(path) = which::which("chromedriver") {
-        return Ok(path);
-    }
-    install_chromedriver(cache, mode.install_permitted())
-}
-
-/// Download and install a pre-built `chromedriver` binary.
-pub fn install_chromedriver(
-    cache: &Cache,
-    installation_allowed: bool,
-) -> Result<PathBuf, failure::Error> {
-    let target = if target::LINUX && target::x86_64 {
-        "linux64"
-    } else if target::MACOS && target::x86_64 {
-        "mac64"
-    } else if target::WINDOWS {
-        "win32"
-    } else {
-        bail!("chromedriver binaries are unavailable for this target")
-    };
-
-    let url = format!(
-        "https://chromedriver.storage.googleapis.com/2.46/chromedriver_{}.zip",
-        target
-    );
-    match get_and_notify(cache, installation_allowed, "chromedriver", &url)? {
-        Some(path) => Ok(path),
-        None => bail!(
-            "No cached `chromedriver` binary found, and could not find a global \
-             `chromedriver` on the `$PATH`. Not installing `chromedriver` because of noinstall \
-             mode."
-        ),
-    }
-}
-
-/// Get the path to an existing `geckodriver`, or install it if no existing
-/// binary is found.
-pub fn get_or_install_geckodriver(
-    cache: &Cache,
-    mode: InstallMode,
-) -> Result<PathBuf, failure::Error> {
-    if let Ok(path) = which::which("geckodriver") {
-        return Ok(path);
-    }
-    install_geckodriver(cache, mode.install_permitted())
-}
-
-/// Download and install a pre-built `geckodriver` binary.
-pub fn install_geckodriver(
-    cache: &Cache,
-    installation_allowed: bool,
-) -> Result<PathBuf, failure::Error> {
-    let (target, ext) = if target::LINUX && target::x86 {
-        ("linux32", "tar.gz")
-    } else if target::LINUX && target::x86_64 {
-        ("linux64", "tar.gz")
-    } else if target::MACOS {
-        ("macos", "tar.gz")
-    } else if target::WINDOWS && target::x86 {
-        ("win32", "zip")
-    } else if target::WINDOWS && target::x86_64 {
-        ("win64", "zip")
-    } else {
-        bail!("geckodriver binaries are unavailable for this target")
-    };
-
-    let url = format!(
-        "https://github.com/mozilla/geckodriver/releases/download/v0.24.0/geckodriver-v0.24.0-{}.{}",
-        target,
-        ext,
-    );
-    match get_and_notify(cache, installation_allowed, "geckodriver", &url)? {
-        Some(path) => Ok(path),
-        None => bail!(
-            "No cached `geckodriver` binary found, and could not find a global `geckodriver` \
-             on the `$PATH`. Not installing `geckodriver` because of noinstall mode."
-        ),
-    }
-}
 
-/// Get the path to an existing `safaridriver`.
+impl curl::easy::Handler for Collector {
-///
+    fn write(&mut self, data: &[u8]) -> Result<usize, curl::easy::WriteError> {
-/// We can't install `safaridriver` if an existing one is not found because
+        self.0.extend_from_slice(data);
-/// Apple does not provide pre-built binaries. However, `safaridriver` *should*
+        Ok(data.len())
-/// be present by default.
-pub fn get_safaridriver() -> Result<PathBuf, failure::Error> {
-    match which::which("safaridriver") {
-        Ok(p) => Ok(p),
-        Err(_) => bail!("could not find `safaridriver` on the `$PATH`"),
     }
 }

src/test/webdriver/chromedriver.rs

@@ -0,0 +1,77 @@
+use super::{get_and_notify, Collector};
+use binary_install::Cache;
+use failure;
+use install::InstallMode;
+use std::path::PathBuf;
+use target;
+
+/// Get the path to an existing `chromedriver`, or install it if no existing
+/// binary is found or if there is a new binary version.
+pub fn get_or_install_chromedriver(
+    cache: &Cache,
+    mode: InstallMode,
+) -> Result<PathBuf, failure::Error> {
+    if let Ok(path) = which::which("chromedriver") {
+        return Ok(path);
+    }
+    install_chromedriver(cache, mode.install_permitted())
+}
+
+/// Download and install a pre-built `chromedriver` binary.
+pub fn install_chromedriver(
+    cache: &Cache,
+    installation_allowed: bool,
+) -> Result<PathBuf, failure::Error> {
+    let target = if target::LINUX && target::x86_64 {
+        "linux64"
+    } else if target::MACOS && target::x86_64 {
+        "mac64"
+    } else if target::WINDOWS {
+        "win32"
+    } else {
+        bail!("chromedriver binaries are unavailable for this target")
+    };
+
+    let url = get_chromedriver_url(target)?;
+
+    match get_and_notify(cache, installation_allowed, "chromedriver", &url)? {
+        Some(path) => Ok(path),
+        None => bail!(
+            "No cached `chromedriver` binary found, and could not find a global \
+             `chromedriver` on the `$PATH`. Not installing `chromedriver` because of noinstall \
+             mode."
+        ),
+    }
+}
+
+/// Get `chromedriver` download URL.
+///
+/// It returns the latest one without checking the installed `Chrome` version
+/// because it's not easy to find out `Chrome` version on `Windows` -
+/// https://bugs.chromium.org/p/chromium/issues/detail?id=158372
+///
+/// The official algorithm for `chromedriver` version selection:
+/// https://chromedriver.chromium.org/downloads/version-selection
+fn get_chromedriver_url(target: &str) -> Result<String, failure::Error> {
+    let chromedriver_version = fetch_chromedriver_version()?;
+    Ok(assemble_chromedriver_url(&chromedriver_version, target))
+}
+
+// ------ `get_chromedriver_url` steps ------
+
+fn fetch_chromedriver_version() -> Result<String, failure::Error> {
+    let mut handle = curl::easy::Easy2::new(Collector(Vec::new()));
+    handle.url("https://chromedriver.storage.googleapis.com/LATEST_RELEASE")?;
+    handle.perform()?;
+
+    let contents = handle.get_ref();
+    Ok(String::from_utf8_lossy(&contents.0).into_owned())
+}
+
+fn assemble_chromedriver_url(chromedriver_version: &str, target: &str) -> String {
+    format!(
+        "https://chromedriver.storage.googleapis.com/{version}/chromedriver_{target}.zip",
+        version = chromedriver_version,
+        target = target,
+    )
+}

src/test/webdriver/geckodriver.rs

@@ -0,0 +1,93 @@
+use super::{get_and_notify, Collector};
+use binary_install::Cache;
+use failure;
+use install::InstallMode;
+use std::path::PathBuf;
+use target;
+
+/// Get the path to an existing `geckodriver`, or install it if no existing
+/// binary is found or if there is a new binary version.
+pub fn get_or_install_geckodriver(
+    cache: &Cache,
+    mode: InstallMode,
+) -> Result<PathBuf, failure::Error> {
+    if let Ok(path) = which::which("geckodriver") {
+        return Ok(path);
+    }
+    install_geckodriver(cache, mode.install_permitted())
+}
+
+/// Download and install a pre-built `geckodriver` binary.
+pub fn install_geckodriver(
+    cache: &Cache,
+    installation_allowed: bool,
+) -> Result<PathBuf, failure::Error> {
+    let (target, ext) = if target::LINUX && target::x86 {
+        ("linux32", "tar.gz")
+    } else if target::LINUX && target::x86_64 {
+        ("linux64", "tar.gz")
+    } else if target::MACOS {
+        ("macos", "tar.gz")
+    } else if target::WINDOWS && target::x86 {
+        ("win32", "zip")
+    } else if target::WINDOWS && target::x86_64 {
+        ("win64", "zip")
+    } else {
+        bail!("geckodriver binaries are unavailable for this target")
+    };
+
+    let url = get_geckodriver_url(target, ext)?;
+
+    match get_and_notify(cache, installation_allowed, "geckodriver", &url)? {
+        Some(path) => Ok(path),
+        None => bail!(
+            "No cached `geckodriver` binary found, and could not find a global `geckodriver` \
+             on the `$PATH`. Not installing `geckodriver` because of noinstall mode."
+        ),
+    }
+}
+
+/// Get `geckodriver` download URL.
+///
+/// It returns the latest one without checking the installed `Firefox` version
+/// - it should be relatively safe because each `geckodriver` supports many `Firefox` versions:
+/// https://firefox-source-docs.mozilla.org/testing/geckodriver/Support.html#supported-platforms
+fn get_geckodriver_url(target: &str, ext: &str) -> Result<String, failure::Error> {
+    // JSON example: `{"id":15227534,"tag_name":"v0.24.0","update_url":"/mozzila...`
+    let latest_tag_json = fetch_latest_geckodriver_tag_json()?;
+    let latest_tag = get_tag_name_from_json(&latest_tag_json)?;
+    Ok(assemble_geckodriver_url(&latest_tag, target, ext))
+}
+
+// ------ `get_geckodriver_url` steps ------
+
+fn fetch_latest_geckodriver_tag_json() -> Result<String, failure::Error> {
+    let mut headers = curl::easy::List::new();
+    headers.append("Accept: application/json")?;
+
+    let mut handle = curl::easy::Easy2::new(Collector(Vec::new()));
+    handle.url("https://github.com/mozilla/geckodriver/releases/latest")?;
+    handle.http_headers(headers)?;
+    // We will be redirected from the `latest` placeholder to the specific tag name.
+    handle.follow_location(true)?;
+    handle.perform()?;
+
+    let contents = handle.get_ref();
+    Ok(String::from_utf8_lossy(&contents.0).into_owned())
+}
+
+fn get_tag_name_from_json(json: &str) -> Result<String, failure::Error> {
+    let json: serde_json::Value = serde_json::from_str(json)?;
+    json.get("tag_name")
+        .and_then(|tag_name| tag_name.as_str().map(ToOwned::to_owned))
+        .ok_or_else(|| failure::err_msg("cannot get `tag_name` from JSON response"))
+}
+
+fn assemble_geckodriver_url(tag: &str, target: &str, ext: &str) -> String {
+    format!(
+        "https://github.com/mozilla/geckodriver/releases/download/{tag}/geckodriver-{tag}-{target}.{ext}",
+        tag=tag,
+        target=target,
+        ext=ext,
+    )
+}

src/test/webdriver/safaridriver.rs

@@ -0,0 +1,13 @@
+use std::path::PathBuf;
+
+/// Get the path to an existing `safaridriver`.
+///
+/// We can't install `safaridriver` if an existing one is not found because
+/// Apple does not provide pre-built binaries. However, `safaridriver` *should*
+/// be present by default.
+pub fn get_safaridriver() -> Result<PathBuf, failure::Error> {
+    match which::which("safaridriver") {
+        Ok(p) => Ok(p),
+        Err(_) => bail!("could not find `safaridriver` on the `$PATH`"),
+    }
+}