alef 0.32.2

Opinionated polyglot binding generator for Rust libraries
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201

use crate::core::template_versions as tv;
use crate::e2e::config::E2eConfig;
use std::fmt::Write as FmtWrite;

// render_app_harness has been moved to a consumer extension
// (the e2e extension). Do not add it back here.

/// Emit an Elixir snippet that sets every `[e2e.env]` entry into the environment
/// using `System.get_env` to check first so a parent runner can override at spawn time.
/// Returns empty when no env vars are configured.
fn render_env_setup_block(e2e_config: &E2eConfig) -> String {
    if e2e_config.env.is_empty() {
        return String::new();
    }
    let mut keys: Vec<&String> = e2e_config.env.keys().collect();
    keys.sort();
    let mut out = String::new();
    for k in keys {
        let v = &e2e_config.env[k];
        out.push_str(&format!(
            "unless System.get_env(\"{}\") do\n  System.put_env(\"{}\", \"{}\")\nend\n",
            k, k, v
        ));
    }
    out.push('\n');
    out
}

/// Resolve the Elixir NIF module that exposes `set_env/2`.
///
/// Mirrors the module-path resolution used elsewhere in the Elixir e2e codegen
/// (see `test_case.rs`): a value containing `.` or starting uppercase is used
/// verbatim; otherwise it is PascalCased. The NIF lives under `<Module>.Native`.
fn elixir_nif_module(e2e_config: &E2eConfig) -> String {
    let raw_module = &e2e_config.call.module;
    let module_path = if raw_module.contains('.') || raw_module.chars().next().is_some_and(|c| c.is_uppercase()) {
        raw_module.clone()
    } else {
        super::values::elixir_module_name(raw_module)
    };
    format!("{module_path}.Native")
}

/// Emit the native env-propagation block and the test-documents chdir.
///
/// Elixir's `System.put_env` (Erlang `os:putenv`) does not reach the native C
/// runtime that an FFI library reads via `getenv`, so each configured `[e2e.env]`
/// entry is also pushed through the binding's `set_env/2` NIF (libc setenv),
/// wrapped in `try/rescue` so suites whose binding lacks the NIF still load.
///
/// The chdir runs from `test_documents_dir` so relative file URIs resolve,
/// mirroring the Python/Go suites. Returns an empty string when no `[e2e.env]`
/// entries are configured — the native propagation and the chdir are only needed
/// by suites that opt into env-driven setup (and the empty case keeps the
/// generated `test_helper.exs` free of any `System.get_env` references).
fn render_native_env_and_chdir(e2e_config: &E2eConfig) -> String {
    if e2e_config.env.is_empty() {
        return String::new();
    }

    let mut out = String::new();

    let nif_module = elixir_nif_module(e2e_config);
    out.push_str("# Erlang os:putenv does not propagate to the native C runtime that an FFI\n");
    out.push_str("# library reads via getenv. Push each value through the binding's set_env NIF\n");
    out.push_str("# (libc setenv) so the native side observes the same environment.\n");
    let mut keys: Vec<&String> = e2e_config.env.keys().collect();
    keys.sort();
    for k in keys {
        let v = &e2e_config.env[k];
        out.push_str("try do\n");
        let _ = writeln!(out, "  {nif_module}.set_env(\"{k}\", \"{v}\")");
        out.push_str("rescue\n");
        out.push_str("  _ -> :ok\n");
        out.push_str("end\n");
    }
    out.push('\n');

    let rel = e2e_config.test_documents_relative_from(1);
    out.push_str("# Tests construct absolute paths via test_documents_path, so no chdir needed.\n");
    out.push_str("# Set ALEF_TEST_DOCUMENTS_DIR for any custom code that may reference it.\n");
    out.push_str("unless System.get_env(\"ALEF_TEST_DOCUMENTS_DIR\") do\n");
    out.push_str("  test_documents_dir = Path.expand(\"");
    out.push_str(&rel);
    out.push_str("\", __DIR__)\n");
    out.push_str("  System.put_env(\"ALEF_TEST_DOCUMENTS_DIR\", test_documents_dir)\n");
    out.push_str("end\n\n");

    out
}

/// Render the non-server-pattern `test/test_helper.exs`.
///
/// Covers the mock-server case (`has_http_tests` = true) and the NIF-only case.
/// The server-pattern (`uses_harness`) branch is owned by a consumer extension
/// via `Extension::emit_e2e`.
pub(super) fn render_test_helper(has_http_tests: bool, e2e_config: &E2eConfig) -> String {
    // Environment variables (including E2E_ALLOW_PRIVATE_NETWORK) must be set BEFORE
    // the Rustler NIF loads (at first module init). render_env_setup_block emits all [e2e.env]
    // vars with System.get_env guards, ensuring they're set early.
    let env_setup = render_env_setup_block(e2e_config);
    let native_and_chdir = render_native_env_and_chdir(e2e_config);

    if has_http_tests {
        let finch_setup = r#"# Start a named Finch pool before ExUnit configured to use HTTP/1 only.
# Tests pass `finch: AlefE2EFinch` on every Req call; the pool's protocol
# selection (via `pools.default.protocols: [:http1]`) is the canonical place
# to pin the wire protocol since Req rejects per-call `:connect_options` when
# `:finch` is set.
{:ok, _} = Finch.start_link(name: AlefE2EFinch, pools: %{:default => [protocols: [:http1]]})

ExUnit.start()

"#;
        let mock_server =
            crate::e2e::template_env::render("elixir/test_helper_mock_server.exs.jinja", minijinja::context!());
        format!("{}{}{}{}", env_setup, native_and_chdir, finch_setup, mock_server)
    } else {
        format!("{}{}ExUnit.start()\n", env_setup, native_and_chdir)
    }
}

pub(super) fn render_mix_exs(
    pkg_name: &str,
    pkg_path: &str,
    dep_mode: crate::e2e::config::DependencyMode,
    has_http_tests: bool,
    has_mock_server_tests: bool,
    has_nif_tests: bool,
    uses_harness: bool,
) -> String {
    let mut out = String::new();
    let _ = writeln!(out, "defmodule E2eElixir.MixProject do");
    let _ = writeln!(out, "  use Mix.Project");
    let _ = writeln!(out);
    let _ = writeln!(out, "  def project do");
    let _ = writeln!(out, "    [");
    let _ = writeln!(out, "      app: :e2e_elixir,");
    let _ = writeln!(out, "      version: \"0.1.0\",");
    let _ = writeln!(out, "      elixir: \"~> 1.14\",");
    let _ = writeln!(out, "      deps: deps()");
    let _ = writeln!(out, "    ]");
    let _ = writeln!(out, "  end");
    let _ = writeln!(out);
    let _ = writeln!(out, "  defp deps do");
    let _ = writeln!(out, "    [");

    // Build the list of deps, then join with commas to avoid double-commas.
    let mut deps: Vec<String> = Vec::new();

    // Add the binding NIF dependency when there are non-HTTP tests.
    if has_nif_tests && !pkg_path.is_empty() {
        let pkg_atom = pkg_name;
        let nif_dep = match dep_mode {
            crate::e2e::config::DependencyMode::Local => {
                format!("      {{:{pkg_atom}, path: \"{pkg_path}\"}}")
            }
            crate::e2e::config::DependencyMode::Registry => {
                // Registry mode: pkg_path is repurposed as the version string.
                format!("      {{:{pkg_atom}, \"{pkg_path}\"}}")
            }
        };
        deps.push(nif_dep);
        // rustler_precompiled provides the precompiled NIF loader.
        deps.push(format!(
            "      {{:rustler_precompiled, \"{rp}\"}}",
            rp = tv::hex::RUSTLER_PRECOMPILED
        ));
        // rustler must be a direct, non-optional dep in the consumer project for
        // `force_build: Mix.env() in [:test, :dev]` to actually fetch the rustler hex
        // package. With `optional: true` mix omits it when no other dep declares it as
        // required, breaking the build-from-source path used by the e2e suite.
        deps.push(format!(
            "      {{:rustler, \"{rustler}\", runtime: false}}",
            rustler = tv::hex::RUSTLER
        ));
    }

    // Add Req + Jason + Finch for HTTP testing, mock-server testing, or
    // server-pattern harness. The test_helper.exs is emitted whenever any of
    // `has_http_tests`, `has_mock_server_tests`, or `uses_harness` is true
    // (see render_test_helper invocation) and always calls
    // Finch.start_link(name: AlefE2EFinch), so all three flags must trigger
    // dep inclusion. Without `has_mock_server_tests` here, projects that use
    // mock-server fixtures via `mock_response` / `client_factory` but no raw
    // http fixtures (and no harness) generate a test_helper.exs that calls
    // Finch without the corresponding mix dep, producing
    // `(UndefinedFunctionError) function Finch.start_link/1 is undefined`
    // at `mix test`.
    if has_http_tests || has_mock_server_tests || uses_harness {
        deps.push(format!("      {{:finch, \"{finch}\"}}", finch = tv::hex::FINCH));
        deps.push(format!("      {{:req, \"{req}\"}}", req = tv::hex::REQ));
        deps.push(format!("      {{:jason, \"{jason}\"}}", jason = tv::hex::JASON));
    }

    let _ = writeln!(out, "{}", deps.join(",\n"));
    let _ = writeln!(out, "    ]");
    let _ = writeln!(out, "  end");
    let _ = writeln!(out, "end");
    out
}