Makes TypeScript a peer dependency

- Moves typescript from a regular to a development dependency
- Declares typescript as a (mandatory) peer dependency, taking the
  current ^-version as the minimum
- Expands the travis ci config so it runs against typescript 3 and 4
- Updates the Dockerfile so it installs typescript (latest) after
  the npm ci.

- Also: adds an .npmrc to make sure the current npm installation &
  upgrade policies (^, package-lock, if I inferred correctly) are
  respected on machines that have a global override for these.

Author: sverweij

.npmrc

@@ -0,0 +1,3 @@
+package-lock=true
+save-exact=false
+save-prefix=^

.travis.yml

@@ -4,9 +4,13 @@ node_js:
   - 12
   - 14
   # TODO - 16 when it is released
+env:
+  - TYPESCRIPT_VERSION=3
+  - TYPESCRIPT_VERSION=4
 notifications:
-    email: false
+  email: false
 script:
+  - npm install --development typescript@$TYPESCRIPT_VERSION
   - npm test
 after_success:
   - npm run report-coverage-to-coveralls

CHANGELOG.md

@@ -14,6 +14,10 @@
 
 - if 0 issues (0 modules with unused exports) then use the default color. (Issue #164)
 - Add an option to stop writing to stdout on success: --silent
+- BREAKING CHANGE: Makes TypeScript a peer dependency (Issue #159)  
+  Migration path:
+  If you already have a version of the TypeScript compiler installed in the same spot as ts-unused-exports no migration steps are necessary (it will work out of the box).
+  Otherwise you'll have to install the TypeScript compiler there yourself (e.g. with `npm i -D typescript`).
 
 ## [6.2.4] - 14 Sep 2020
 
@@ -52,7 +56,7 @@
 ### Added
 
 - Handle dynamic imports within a TSX div or fragment
-- Add basic support for export * as namespace.
+- Add basic support for export \* as namespace.
 
 ## [6.1.2] - 1 Apr 2020
 

Dockerfile

@@ -7,6 +7,7 @@ RUN apk add bash
 COPY ["package.json", "package-lock.json", "/usr/src/"]
 
 RUN CI=1 npm ci
+RUN npm install --development typescript
 
 COPY [".*", "*.json", "/usr/src/"]
 COPY ["bin/", "/usr/src/bin/"]

README.md

@@ -73,6 +73,8 @@ Note that if `ts-unused-exports` is called without files, the files will be read
 
 `ts-unused-exports` also resolves path aliases specified in tsconfig's `paths` object.
 
+As of version 7.0.0 the TypeScript compiler is a _peer dependency_ of `ts-unused-exports`. This means that if the TypeScript compiler is not already in the same spot as `ts-unused-exports`, you have to install it yourself (e.g. with `npm i -D typescript`).
+
 ## Why should I use this?
 
 If you've ever used `tslint`'s [no-unused-variable](http://palantir.github.io/tslint/rules/no-unused-variable/) rule you already known how awesome it is. What this rule does is detect code in your modules that is not being used so that you can remove it.

package-lock.json

@@ -50,11 +50,19 @@
     "nyc": "^15.0.0",
     "pickled-cucumber": "^2.0.14",
     "prettier": "^1.19.1",
-    "ts-node": "^8.8.1"
+    "ts-node": "^8.8.1",
+    "typescript": "^3.8.3"
   },
   "dependencies": {
     "chalk": "^3.0.0",
-    "tsconfig-paths": "^3.9.0",
-    "typescript": "^3.8.3"
+    "tsconfig-paths": "^3.9.0"
+  },
+  "peerDependencies": {
+    "typescript": ">=3.8.3"
+  },
+  "peerDependenciesMeta": {
+    "typescript": {
+      "optional": false
+    }
   }
 }