feat: add 1058-1062

docs/1058.md

@@ -1,4 +1,31 @@
 ---
 title: "The return type of an async function must either be a valid promise or must not contain a callable 'then' member."
 category: error
+tags:
+- async
+- syntax-error
+- promises
+related:
+- 1059
+- 1060
 ---
+
+Async functions cannot return objects with a callable then property as
+Javascript aggressively flattens promises. Therefore the following is an error:
+
+```ts
+class A {
+  async test() {
+    return {
+      then() {},
+    };
+  }
+}
+```
+
+### See also
+
+- [StackOverflow - Typescript error when function return type is Promise<{ then: () => void }>](https://stackoverflow.com/questions/47111363/typescript-error-when-function-return-type-is-promise-then-void)
+- [StackOverflow - Fulfill (don't resolve) promise with another promise](https://stackoverflow.com/questions/32168194/fulfill-dont-resolve-promise-with-another-promise)
+- [Monads for the Rest of Us - Why Promises are not Monads](https://gist.github.com/fatcerberus/beae4d15842071eab24fca2f0740c2ef#monads-its-the-law)
+- [MDN - `Promise`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)

docs/1058_fix_01.md

@@ -0,0 +1,16 @@
+---
+title: "Rename the method/property."
+---
+
+The best fix for this error is to rename the `then` method on the object you are
+returning to something else. `chain` or `map` might be appropriate:
+
+```ts
+class A {
+  async test() {
+    return {
+      chain() {},
+    };
+  }
+}
+```

docs/1059.md

@@ -1,4 +1,14 @@
 ---
 title: "A promise must have a 'then' method."
 category: error
+tags:
+- promise
+- typescript-only
+- async
+related:
+- 1058
+- 1060
 ---
+
+This is caused by the global `Promise` not containing a callable `then` method
+and therefore not supporting `async`/`await` downlevel emit.

docs/1059_fix_01.md

@@ -0,0 +1,7 @@
+---
+title: "Issue with types."
+---
+
+The most common fix for this is that is the types for the 3rd party promise
+library is not configured properly. Refer to current documentation for using the
+3rd party promise library.

docs/1060.md

@@ -1,4 +1,11 @@
 ---
 title: "The first parameter of the 'then' method of a promise must be a callback."
 category: error
+tags:
+- promise
+- typescript-only
+- async
 ---
+
+This is caused by the global `Promise` not having a compatible signature to
+support `async`/`await` downlevel emit.

docs/1060_fix_01.md

@@ -0,0 +1,8 @@
+---
+title: "Issue with promise library."
+---
+
+Either the 3rd party promise library cannot be used with TypeScript to down
+level emit `async`/`await` or there is a configuration issue with the library
+that is not allowing TypeScript to understand it will work. Consult the current
+documentation for the 3rd party promise library.

docs/1061.md

@@ -1,4 +1,17 @@
 ---
 title: "Enum member must have initializer."
 category: error
+tags:
+- enums
+- typescript-only
 ---
+
+When an enum contains string members, TypeScript cannot infer the value of
+members. Therefore the following will error:
+
+```ts
+enum A {
+  a = "1",
+  b,
+}
+```

docs/1061_fix_01.md

@@ -0,0 +1,12 @@
+---
+title: "Provide an initializer for each member."
+---
+
+Explicitly initialize the member:
+
+```ts
+enum A {
+  a = "1",
+  b = "2",
+}
+```

docs/1062.md

@@ -1,4 +1,23 @@
 ---
 title: "Type is referenced directly or indirectly in the fulfillment callback of its own 'then' method."
 category: error
+tags:
+- promise
+- async
 ---
+
+When implementing a non-native promise type, if the type references itself in
+the `then`` method, this error will occur:
+
+```ts
+declare class BadPromise {
+  then(
+    onfulfilled: (value: BadPromise) => any,
+    onrejected: (error: any) => any,
+  ): BadPromise;
+}
+
+async function test() {
+  await new BadPromise();
+}
+```

docs/1062_fix_01.md

@@ -0,0 +1,5 @@
+---
+title: "Don't use a recursive type."
+---
+
+To fix the error, don't use a recursive type in the definition of the promise.