@6river/context - npm Package Compare versions

Comparing version 1.0.0-beta.2 to 1.0.0-beta.3

dist/src/context.d.ts

@@ -6,2 +6,3 @@ export declare type ErrorType = Error | null;
     error(): ErrorType;
+    value<K, V>(key: K): V | null;
 }
@@ -16,1 +17,2 @@ export declare const cancelledErr: Error;
 export declare function withTimeout(parent: Context, timeout: number): [Context, CancelFunc];
+export declare function withValue<K, V>(parent: Context, key: K, value: V): Context;

dist/src/context.js

@@ -23,2 +23,5 @@ "use strict";
     }
+    value(key) {
+        return null;
+    }
 }
@@ -78,8 +81,14 @@ const backgroundCtx = new EmptyCtx();
 function parentCancelCtx(parent) {
-    if (parent instanceof CancelCtx) {
-        return parent;
+    let c = parent;
+    for (;;) {
+        if (c instanceof CancelCtx) {
+            return c;
+        }
+        else if (c instanceof ValueCtx) {
+            c = c.ctx;
+        }
+        else {
+            return null;
+        }
     }
-    else {
-        return null;
-    }
 }
@@ -118,2 +127,5 @@ // removeChild removes a context from its parent.
     }
+    value(key) {
+        return this.parent.value(key);
+    }
     // cancel resolves ctx.done() promise, cancels each of c's children, and, if
@@ -214,2 +226,34 @@ // removeFromParent is true, removes ctx from its parent's children.
 }
+// A ValueCtx carries a key-value pair.
+// It implements Value for that key and delegates all other calls to the embedded Context.
+class ValueCtx {
+    constructor(ctx, key, val) {
+        this.ctx = ctx;
+        this.key = key;
+        this.val = val;
+    }
+    deadline() {
+        return this.ctx.deadline();
+    }
+    done() {
+        return this.ctx.done();
+    }
+    error() {
+        return this.ctx.error();
+    }
+    value(key) {
+        if (this.key === key) {
+            return (this.val);
+        }
+        return this.ctx.value(key);
+    }
+}
+// withValue returns a copy of parent in which the value associated with key is val.
+//
+// Use context Values only for request-scoped data that transits processes and
+// APIs, not for passing optional parameters to functions.
+function withValue(parent, key, value) {
+    return new ValueCtx(parent, key, value);
+}
+exports.withValue = withValue;
 //# sourceMappingURL=context.js.map

dist/test/context.test.js

@@ -140,3 +140,13 @@ "use strict";
     });
+    describe('withValue', function () {
+        it('should create context with embedded value accessible by the key', function () {
+            const root = context_1.withValue(context_1.background(), 'foo', 'bar');
+            const [child, cancelChild] = context_1.withCancel(root);
+            const grandChild = context_1.withValue(child, 'baz', 0);
+            const [grandGrandChild, cancelGrandGrand] = context_1.withTimeout(grandChild, 10000);
+            expect(grandGrandChild.value('baz')).to.equal(0);
+            expect(grandGrandChild.value('foo')).to.equal('bar');
+        });
+    });
 });
 //# sourceMappingURL=context.test.js.map

package.json

@@ -50,3 +50,3 @@ {
   "types": "./dist/src/context.d.ts",
-  "version": "1.0.0-beta.2"
+  "version": "1.0.0-beta.3"
 }

src/context.ts

@@ -28,2 +28,11 @@ export type ErrorType = Error | null;
 	error(): ErrorType;
+
+	// value returns the value associated with this context for key, or null
+	// if no value is associated with key. Successive calls to Value with
+	// the same key returns the same result.
+	//
+	// Use context values only for request-scoped data that transits
+	// processes and API boundaries, not for passing optional parameters to
+	// functions.
+	value<K, V>(key: K): V | null;
 }
@@ -57,2 +66,7 @@
 	}
+
+
+	value<K, V>(key: K): V | null {
+		return null;
+	}
 }
@@ -131,6 +145,12 @@
 function parentCancelCtx(parent: Context): CancelCtx | null {
-	if (parent instanceof CancelCtx) {
-		return parent;
-	} else {
-		return null;
+	let c = parent;
+
+	for (;;) {
+		if (c instanceof CancelCtx) {
+			return c;
+		} else if (c instanceof ValueCtx) {
+			c = c.ctx;
+		} else {
+			return null;
+		}
 	}
@@ -179,2 +199,6 @@ }
 
+	value<K, V>(key: K): V | null {
+		return this.parent.value<K, V>(key);
+	}
+
 	// cancel resolves ctx.done() promise, cancels each of c's children, and, if
@@ -290,1 +314,34 @@ // removeFromParent is true, removes ctx from its parent's children.
 }
+
+// A ValueCtx carries a key-value pair.
+// It implements Value for that key and delegates all other calls to the embedded Context.
+class ValueCtx implements Context {
+	constructor(public ctx: Context, private key: any, private val: any) {}
+
+	deadline(): Date | null {
+		return this.ctx.deadline();
+	}
+
+	done(): Promise<void> {
+		return this.ctx.done();
+	}
+
+	error(): ErrorType {
+		return this.ctx.error();
+	}
+
+	value<K, V>(key: K): V | null {
+		if (this.key === key) {
+			return <V>(this.val);
+		}
+		return this.ctx.value<K, V>(key);
+	}
+}
+
+// withValue returns a copy of parent in which the value associated with key is val.
+//
+// Use context Values only for request-scoped data that transits processes and
+// APIs, not for passing optional parameters to functions.
+export function withValue<K, V>(parent: Context, key: K, value: V): Context {
+	return new ValueCtx(parent, key, value);
+}

No alert changes

Improved metrics

Total package byte prevSize

38458

14.43%

Lines of code

706

16.89%

No dependency changes