Fix zen-observable typescript import

[dobesv]

Because zen observable uses the export = Observable, it should be imported using the form import Observable = require('zen-observable');.

See https://www.typescriptlang.org/docs/handbook/modules.html under the heading "export = and import = require()":

When exporting a module using export =, TypeScript-specific import module = require("module") must be used to import the module.

This error occurs if your tsconfig has

    "esModuleInterop": true,

Setting that option to false prevents the error.

[dobesv]

See also #558

[dobesv]

See also #248

[dobesv]

See also #380 as a possible alternative fix.

[dobesv]

See also #515

[dobesv]

See also #511

[tannerbaum]

I'm not sure if it is appropriate to comment here, but I have a suspicion that this fix could solve an error that has haunted me for the last three days:

ERROR in [at-loader] ./node_modules/@types/zen-observable/index.d.ts:8:9 TS2687: All declarations of 'observable' must have identical modifiers.

Really hope this PR can be merged.

Edit: actually this was a result of conflicting type imports. But I am glad that the pr has been resolved at least

[dobesv]

It seems like recent changes to master have probably made this PR obsolete.

[nicky-lenaers]

Same issue as @THoisington , still present in 1.2.2

EDIT:
The RXJS package has also updated this, see the PR

[dobesv]

@nicky-lenaers You should probably comment on one of the related issues. This PR would have to be redone since the code it was based on has changed in a significant way.

[tannerbaum]

@nicky-lenaers There is also a PR in zen-observable. For me it was specifically @types/node adding readonly and @types/zen-observable was missing it. Seems like things can really get messy with @types!