Support TypeScript 3.7

[filipesilva]

While trying to update Angular to typescript@3.7.0-beta in angular/angular#32962, I came across this error emitted by tsickle:

Error: rest parameter does not resolve to a reference type
    at ModuleTypeTranslator.getFunctionTypeJSDoc (/home/circleci/.cache/bazel/_bazel_circleci/9ce5c2144ecf75d11717c0aa41e45a8d/sandbox/processwrapper-sandbox/378/execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.sh.runfiles/npm/node_modules/tsickle/src/module_type_translator.js:424:39)
    at visitFunctionLikeDeclaration (/home/circleci/.cache/bazel/_bazel_circleci/9ce5c2144ecf75d11717c0aa41e45a8d/sandbox/processwrapper-sandbox/378/execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.sh.runfiles/npm/node_modules/tsickle/src/jsdoc_transformer.js:527:75)
    at visitor (/home/circleci/.cache/bazel/_bazel_circleci/9ce5c2144ecf75d11717c0aa41e45a8d/sandbox/processwrapper-sandbox/378/execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.sh.runfiles/npm/node_modules/tsickle/src/jsdoc_transformer.js:913:36)
    at visitNodes (/home/circleci/.cache/bazel/_bazel_circleci/9ce5c2144ecf75d11717c0aa41e45a8d/sandbox/processwrapper-sandbox/378/execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.sh.runfiles/npm/node_modules/typescript/lib/typescript.js:70546:48)
    at visitLexicalEnvironment (/home/circleci/.cache/bazel/_bazel_circleci/9ce5c2144ecf75d11717c0aa41e45a8d/sandbox/processwrapper-sandbox/378/execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.sh.runfiles/npm/node_modules/typescript/lib/typescript.js:70579:22)
...

This corresponds to the following code in tsickle:

                        if (type.flags & ts.TypeFlags.Object &&
                            type.objectFlags & ts.ObjectFlags.Reference) {
                            const typeRef = type;
                            if (!typeRef.typeArguments) {
                                throw new Error('rest parameter does not resolve to a reference type');
                            }
                            type = typeRef.typeArguments[0];
                        }

This seems to be another instance of microsoft/TypeScript#33693, a breaking change that affects Angular. It's easy to work around though:

before:

          const typeReference = type as ts.TypeReference;
          if (typeReference.typeArguments && typeReference.typeArguments.length === 1) {
            return typeReference.typeArguments[0].symbol;
          }

after

          const typeReference = type as ts.TypeReference;
          const typeArguments = this.checker.getTypeArguments(typeReference);
          if (typeArguments.length === 1) {
            return typeArguments[0].symbol;
          }

[brad4d]

Created Google internal issue http://b/143068853

[chadbr]

Looking forward to 3.7 support! ❤️

[filipesilva]

This seems to be addressed in the ts37 branch (a1e7cce) and released as tsickle@0.38.0.

[mprobst]

That's correct @filipesilva