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✨ Add Main api (#1102)
In order to implement the inspector, we need to be able to wrap code around the main function that will run around the main entry point. This lets you do one time setup and one-time teardown.
1 parent a3896da commit 33c7fae

2 files changed

Lines changed: 106 additions & 89 deletions

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‎lib/api.ts‎

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -14,8 +14,13 @@ interface ScopeApi {
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delete<T>(scope: Scope, context: Context<T>): boolean;
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}
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interface MainApi {
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main(body: (args: string[]) => Operation<void>): Promise<void>;
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}
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interface Apis {
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Scope: Api<ScopeApi>;
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Main: Api<MainApi>;
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}
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export const api: Apis = {
@@ -31,4 +36,9 @@ export const api: Apis = {
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return delete (scope as ScopeInternal).contexts[context.name];
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},
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}),
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Main: createApi<MainApi>("Main", {
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main() {
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throw new TypeError(`missing handler for "main()"`);
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},
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}),
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};

‎lib/main.ts‎

Lines changed: 96 additions & 89 deletions
Original file line numberDiff line numberDiff line change
@@ -2,8 +2,9 @@ import { createContext } from "./context.ts";
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import type { Operation } from "./types.ts";
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import { callcc } from "./callcc.ts";
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import { run } from "./run.ts";
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import { useScope } from "./scope.ts";
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import { global, useScope } from "./scope.ts";
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import { call } from "./call.ts";
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import { api } from "./api.ts";
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/**
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* Halt process execution immediately and initiate shutdown. If a message is
@@ -60,103 +61,109 @@ export function* exit(status: number, message?: string): Operation<void> {
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* @since 3.0
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*/
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63-
export async function main(
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export function main(
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body: (args: string[]) => Operation<void>,
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): Promise<void> {
66-
let hardexit = (_status: number) => {};
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let result = await run(() =>
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callcc<Exit>(function* (resolve) {
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// action will return shutdown immediately upon resolve, so stash
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// this function in the exit context so it can be called anywhere.
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yield* ExitContext.set(resolve);
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// this will hold the event loop and prevent runtimes such as
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// Node and Deno from exiting prematurely.
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let interval = setInterval(() => {}, Math.pow(2, 30));
77-
78-
let scope = yield* useScope();
79-
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try {
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let interrupt = {
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SIGINT: () =>
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scope.run(() => resolve({ status: 130, signal: "SIGINT" })),
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SIGTERM: () =>
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scope.run(() => resolve({ status: 143, signal: "SIGTERM" })),
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};
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yield* withHost({
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*deno() {
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hardexit = (status) => Deno.exit(status);
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try {
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Deno.addSignalListener("SIGINT", interrupt.SIGINT);
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/**
94-
* Windows only supports ctrl-c (SIGINT), ctrl-break (SIGBREAK), and ctrl-close (SIGUP)
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*/
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if (Deno.build.os !== "windows") {
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Deno.addSignalListener("SIGTERM", interrupt.SIGTERM);
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}
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yield* body(Deno.args.slice());
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} finally {
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Deno.removeSignalListener("SIGINT", interrupt.SIGINT);
102-
if (Deno.build.os !== "windows") {
103-
Deno.removeSignalListener("SIGTERM", interrupt.SIGTERM);
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return api.Main.invoke(global, "main", [body]);
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}
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global.around(api.Main, {
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async main([body]) {
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let hardexit = (_status: number) => {};
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74+
let result = await run(() =>
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callcc<Exit>(function* (resolve) {
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// action will return shutdown immediately upon resolve, so stash
77+
// this function in the exit context so it can be called anywhere.
78+
yield* ExitContext.set(resolve);
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80+
// this will hold the event loop and prevent runtimes such as
81+
// Node and Deno from exiting prematurely.
82+
let interval = setInterval(() => {}, Math.pow(2, 30));
83+
84+
let scope = yield* useScope();
85+
86+
try {
87+
let interrupt = {
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SIGINT: () =>
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scope.run(() => resolve({ status: 130, signal: "SIGINT" })),
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SIGTERM: () =>
91+
scope.run(() => resolve({ status: 143, signal: "SIGTERM" })),
92+
};
93+
94+
yield* withHost({
95+
*deno() {
96+
hardexit = (status) => Deno.exit(status);
97+
try {
98+
Deno.addSignalListener("SIGINT", interrupt.SIGINT);
99+
/**
100+
* Windows only supports ctrl-c (SIGINT), ctrl-break (SIGBREAK), and ctrl-close (SIGUP)
101+
*/
102+
if (Deno.build.os !== "windows") {
103+
Deno.addSignalListener("SIGTERM", interrupt.SIGTERM);
104+
}
105+
yield* body(Deno.args.slice());
106+
} finally {
107+
Deno.removeSignalListener("SIGINT", interrupt.SIGINT);
108+
if (Deno.build.os !== "windows") {
109+
Deno.removeSignalListener("SIGTERM", interrupt.SIGTERM);
110+
}
104111
}
105-
}
106-
},
107-
*node() {
108-
// Annotate dynamic import so that webpack ignores it.
109-
// See https://webpack.js.org/api/module-methods/#webpackignore
110-
let { default: process } = yield* call(() =>
111-
import(/* webpackIgnore: true */ "node:process")
112-
);
113-
hardexit = (status) => process.exit(status);
114-
try {
115-
process.on("SIGINT", interrupt.SIGINT);
116-
if (process.platform !== "win32") {
117-
process.on("SIGTERM", interrupt.SIGTERM);
112+
},
113+
*node() {
114+
// Annotate dynamic import so that webpack ignores it.
115+
// See https://webpack.js.org/api/module-methods/#webpackignore
116+
let { default: process } = yield* call(() =>
117+
import(/* webpackIgnore: true */ "node:process")
118+
);
119+
hardexit = (status) => process.exit(status);
120+
try {
121+
process.on("SIGINT", interrupt.SIGINT);
122+
if (process.platform !== "win32") {
123+
process.on("SIGTERM", interrupt.SIGTERM);
124+
}
125+
yield* body(process.argv.slice(2));
126+
} finally {
127+
process.off("SIGINT", interrupt.SIGINT);
128+
if (process.platform !== "win32") {
129+
process.off("SIGTERM", interrupt.SIGINT);
130+
}
118131
}
119-
yield* body(process.argv.slice(2));
120-
} finally {
121-
process.off("SIGINT", interrupt.SIGINT);
122-
if (process.platform !== "win32") {
123-
process.off("SIGTERM", interrupt.SIGINT);
132+
},
133+
*browser() {
134+
try {
135+
self.addEventListener("unload", interrupt.SIGINT);
136+
yield* body([]);
137+
} finally {
138+
self.removeEventListener("unload", interrupt.SIGINT);
124139
}
125-
}
126-
},
127-
*browser() {
128-
try {
129-
self.addEventListener("unload", interrupt.SIGINT);
130-
yield* body([]);
131-
} finally {
132-
self.removeEventListener("unload", interrupt.SIGINT);
133-
}
134-
},
135-
});
136-
137-
yield* exit(0);
138-
} catch (error) {
139-
yield* resolve({ status: 1, error: error as Error });
140-
} finally {
141-
clearInterval(interval);
140+
},
141+
});
142+
143+
yield* exit(0);
144+
} catch (error) {
145+
yield* resolve({ status: 1, error: error as Error });
146+
} finally {
147+
clearInterval(interval);
148+
}
149+
})
150+
);
151+
152+
if (result.message) {
153+
if (result.status === 0) {
154+
console.log(result.message);
155+
} else {
156+
console.error(result.message);
142157
}
143-
})
144-
);
145-
146-
if (result.message) {
147-
if (result.status === 0) {
148-
console.log(result.message);
149-
} else {
150-
console.error(result.message);
151158
}
152-
}
153159

154-
if (result.error) {
155-
console.error(result.error);
156-
}
160+
if (result.error) {
161+
console.error(result.error);
162+
}
157163

158-
hardexit(result.status);
159-
}
164+
hardexit(result.status);
165+
},
166+
}, { at: "min" });
160167

161168
const ExitContext = createContext<(exit: Exit) => Operation<void>>("exit");
162169

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