"use strict" and source map are emitted to json files that are imported as a module

[marcelh-gh]

TypeScript Version: 3.0.0-dev.201xxxxx

Search Terms: json use strict

the "use strict" and the source map in the emitted json cause errors during runtime....

[mhegazy]

Duplicate of #24514.

Fix should be in typescript@next today, and in typescript@2.9.2 next week.

[marcelh-gh]

sorry, I did not see it fixed in typescript@next then and after just updating to 2.9.2 now it also still persists.

[mhegazy]

i am unable to reproduce this locally on typescript@2.9.2. can you please share repro steps?

[marcelh-gh]

hmm...
I just have something like import setup from "./setup.json"; in a .ts file and the new compiler option resolveJsonModule set to true.
The resulting copy of the imported json file is emitted with the use strict and sourcemap - just as before.

in case there is a conflict with some other compiler option, here is my config:

{
    "compilerOptions": {
        "module": "commonjs",
        "strict": true,
        "strictPropertyInitialization": false,
        "noUnusedParameters": true,
        "removeComments": false,
        "preserveConstEnums": true,
        "sourceMap": true,
        "target": "ES2017",
        "outDir": "./compiledJS",
        "experimentalDecorators": true,
        "emitDecoratorMetadata": true,
        "resolveJsonModule": true,
        "esModuleInterop": true,
        "pretty": true,
        "plugins": [
            {
                "name": "tslint-language-service",
                "alwaysShowRuleFailuresAsWarnings": false,
                "ignoreDefinitionFiles": true,
                "supressWhileTypeErrorsPresent": false,
                "mockTypeScriptVersion": false
            }
        ]
    },
    "exclude": [
        "node_modules",
        "compiledJS",
        "playground",
        "documentation",
        "unitTesting",
        "gulpfile.js",
        "lib",
        "bundle.js",
        "**/*/*.quokka.ts"
    ]
}

[mhegazy]

c:\test\24733>type tsconfig.json
{
    "compilerOptions": {
        "module": "commonjs",
        "strict": true,
        "strictPropertyInitialization": false,
        "noUnusedParameters": true,
        "removeComments": false,
        "preserveConstEnums": true,
        "sourceMap": true,
        "target": "ES2017",
        "outDir": "./compiledJS",
        "experimentalDecorators": true,
        "emitDecoratorMetadata": true,
        "resolveJsonModule": true,
        "esModuleInterop": true,
        "pretty": true,
        "plugins": [
            {
                "name": "tslint-language-service",
                "alwaysShowRuleFailuresAsWarnings": false,
                "ignoreDefinitionFiles": true,
                "supressWhileTypeErrorsPresent": false,
                "mockTypeScriptVersion": false
            }
        ]
    },
    "exclude": [
        "node_modules",
        "compiledJS",
        "playground",
        "documentation",
        "unitTesting",
        "gulpfile.js",
        "lib",
        "bundle.js",
        "**/*/*.quokka.ts"
    ]
}

c:\test\24733>type a.ts
import x = require("./a.json")
x.n;
x.a

c:\test\24733>type a.json
{
    "a": 0,
    "n": "s",
}

c:\test\24733>tsc --v
Version 2.9.2

c:\test\24733>tsc

c:\test\24733>type .\compiledJS\a.json
{
    "a": 0,
    "n": "s"
}

[marcelh-gh]

the only difference I see: you wrote import x = require("./a.json") where I did import x from "./a.json";
Everything works fine in my case too - besides the mentioned problem...

[mhegazy]

c:\test\24733>type a.ts
import x from "./a.json";
x.n;
x.a

c:\test\24733>tsc --v
Version 2.9.2

c:\test\24733>tsc

c:\test\24733>type .\compiledJS\a.json
{
    "a": 0,
    "n": "s"
}

[marcelh-gh]

wait a sec. seems the jsons just dont get overwritten if they already exist in the output folder!

[marcelh-gh]

nope. if I use the import from syntax it does not work for me. only with the import x=require....
strange....

[mhegazy]

can you provide a repro project we can look at?

[marcelh-gh]

i literally just used the same files as you in an empty project just now....

[mhegazy]

are u sure you are using 2.9.2?

[marcelh-gh]

yeah sure.... tsc --v ;-)

ok.. I did uninstall and reinstall typescript. now it works regardless of the syntax.
actually I had a similar case happen long time ago when updating from TS 2.1...

sorry to have wasted your time! cheers, marcel