Add an off-by-default 'unstable' flag (#202)

* Add an off-by-default 'unstable' flag

* Remove explicit web framework feature names

Having forgotten that deps and features can't have the same name,
attempts to better document all the features in one place were
misplaced.

* Split up tests on Travis

`cargo test` doesn't allow `--workspace` and `--features`
simultaneously, so we're forced to test each package separately in order
to manually specify features (or in this case, test everything but
unstable)

* Update Travis Config

- Document the state of Cargo workspaces and features
- Update the benchmarks to trickle down the 'unstable' feature

.travis.yml

@@ -9,7 +9,15 @@ jobs:
         - |
           RUN_CLIPPY=true
           rustup component add clippy --toolchain=nightly || RUN_CLIPPY=false
-        - cargo test --all --all-features
+        # As of right now, these need to be tested individually becuase `--workspace`
+        # (which is implied by `workspace = true`) cannot be used with `--features`
+        # This _may_ be resolved with the `--package` flag, however this requires
+        # opting in to a `-Z` unstable feature as of time of commit.
+        #
+        # Follow https://github.com/rust-lang/cargo/issues/5364 for updates.
+        - cargo test --manifest-path maud/Cargo.toml --features actix-web,iron,rocket
+        - cargo test --manifest-path maud_htmlescape/Cargo.toml
+        - cargo test --manifest-path maud_macros/Cargo.toml
         - |
           if $RUN_CLIPPY; then
             CLIPPY_STATUS=0
@@ -18,9 +26,12 @@ jobs:
             done
             (exit $CLIPPY_STATUS)
           fi
+    - name: "Unstable"
+      script:
+        - cargo test --all --all-features
     - name: "Benchmarks"
       script:
-        - (cd benchmarks && cargo test --benches)
+        - (cd benchmarks && cargo test --benches --features unstable)
     - name: "Documentation"
       script:
         - (cd docs && make -j$(nproc))

benchmarks/Cargo.toml

@@ -4,6 +4,9 @@ version = "0.1.2"
 authors = ["Chris Wong <lambda.fairy@gmail.com>"]
 edition = "2018"
 
+[features]
+unstable = ["maud/unstable"]
+
 [dependencies]
 maud = { path = "../maud" }
 handlebars = "*"

maud/Cargo.toml

@@ -12,8 +12,14 @@ categories = ["template-engine"]
 edition = "2018"
 
 [features]
+default = []
+
+# Web framework integrations
 actix-web = ["actix-web-dep", "futures"]
 
+# Unstable features
+unstable = []
+
 [dependencies]
 maud_htmlescape = { version = "0.17.0", path = "../maud_htmlescape" }
 maud_macros = { version = "0.22.0", path = "../maud_macros" }